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This chapter is concerned with the use of the microscope not only in the identification of foodstuffs but also in the quantification of their components. The preparation of a specimen for viewing may be by far the most important operation in microscopy. The mode of preparation will obviously depend on the purpose of the viewer, and it is self-evident that it should be designed to conserve and even enhance the specific features to be observed. For most general observations it is of particular interest to see the contents of cells and tissues, their positional relationships, and their dimensions. For this kind of observation, when the food material is reasonably tender, the classical paraffin method is generally used. Paraffin embedment often results in a loss of enzyme activity, a loss of lipids, shrinking, and presumably hardening because of dehydration during the process of transfer into paraffin.

The white muscle of the Sacramento blackfish (Orthodon microlepidotus) was processed by freezing, dehydration, and cooking. Myosin was extracted immediately afterwards or following a period of storage in order to examine evidence for denaturation. The tests used were the solubility of whole muscle protein and the intrinsic viscosity, isoelectric point, ATPase activity, ultra-violet absorption spectrum, and optical rotatory dispersion of purified myosin extract. Almost all measures used showed that denaturation increased in the order: fresh < frozen < frozen-stored < dehydrated < dehydrated-stored < cooked.

Soluble myosin and insoluble protein (i. e., soluble only in 5 % sodium dodecyl sulfate) were obtained from fresh and processed Sacramento blackfish and analyzed for the existence of possible cross-links. Free sulfhydryl groups decreased somewhat in freezing and more in frozen storage. None were present after dehydration or cooking nor in any insoluble fractions, so that presumably these were oxidized in the formation of cross-links. Ester bonds were much more numerous in insoluble protein than in soluble myosin, but their relative content was not clearly related to processing. Aldehyde groups decreased in myosin after cooking and dehydration, and were absent from insoluble protein. The presumptive Schiff base content was somewhat greater in soluble protein than in myosin and appeared to increase upon freezing and dehydration.

Summary The cuticle of immature and mature tomato fruit is covered by a very thin layer of epicuticular wax. The total cuticular domain, which is 4-10 μm thick, is composed of 2 main regions: (1) A cutinized layer just above the secondary wall of the epidermal cell consists of several strata of deeply staining, globular materials surrounded by non-staining interstices in which dark, tangential, very thin striae are deployed; and (2) a cuticle outside this layer. The cuticle is at first electron lucent mostly but does also have elongated groups of parallel dark striae, 7 nm thick, which are principally tangential. During ripening the cuticle and the cutinized layer achieve similarity in structure, both having irregularly-sized, electron-opaque tangential lamellae, with occasional radial striae. Within the epidermal cell, cutin cystoliths grow down into the secondary wall in the form of vertical hanging prongs or pegs. When they span the cell lumen completely, from outer wall to inner wall, the cystoliths become essentially trabeculae. KMnO4, with or without prior fixation with Gilson stain, is taken up strongly by certain lipoidal components of the cuticle.

The pistil in the flowers of the Iphigenieae (Camptorrhiza, Iphigenia, Omithoglossum) is usually tricarpellate. The carpels are coherent generally, with closed sutures and seemingly bitegmic ovules.Camptorrhiza differs from the others in having a single compound style. The pistils of most species of these genera have a common vascular structure: three dorsal bundles which run into the style(s), a number of lateral bundles, six placental bundles, and up to three compound septal bundles. The latter nine bundles usually differentiate from a central vascular plexus above the base of the locules. There may be fewer than three septal bundles in some specieS. When present, the septal bundles usually die out in the ovuliferous region, but in some cases they persist to the apex of the locules.

Summary Deposition of the secondary wall in the palisade cells of the testa of lima bean seeds appears to involve the endoplasmic reticulum primarily. Although the principal component of that wall is highly oriented and highly crystalline cellulose, virtually no microtubules appeared during cell growth and maturation. Some indications were found that ribosome aggregation in the cytoplasm was associated with the origin of lamellae of the endoplasmic reticulum. Ribosome-like bodies were also prominent at the plasmalemma during formation of the secondary wall.

Tepallary and staminal vascularization in a random sample of the Wurmbaeoideae was eomprised of three vascular bundles per tepal and one per stamen, as in the Rosaceae. The structural similarity of the vascularization of the carpel of the Wurmbaeoideae with that of the Rosaceae is mentioned with the tentative implication of a common ancestry.

Most Helonieae have only slight septal indentations between the three carpels: in Xerophyllum deep septal clefts extend centripetally and completely enclosed, narrow septal pockets occur in Metanarthecium. Other unique generic features are found: tepallary-staminal nectarial glands in Heloniopsis, zygomorphy in Chionographis, and dioecism in Chamaelirium. The carpels are biovulate in Chionographis; there are two to several ovules per carpel in Xerophyllum; 8–12 ovules occur in the carpel of Chamaelirium; and numerous bitegmic ovules are borne in many longitudinal rows on enlarged placentae in Helonias, Heloniopsis, Metanarthecium, and Ypsilandra. Except for Metanarthecium, this last-named group of genera displays a near ring composed of ‘accessory’ placental bundles and a compound septal bundle (with normally oriented xylem and phloem) in cross-section at the inner edge of each septum. Ventral bundles occur in the other four genera.

The starch grain of Dieffenbachia seguine has the shape of an elongated, flat rod, one of whose ends is rounded and the other square. Its hilum lies near the rounded end of the grain. The molecules of the central core are parallel to the long axis of the grain while those of the peripheral layer tend to be nearly perpendicular (radial) to that axis. Gelatinization makes evident a fibrillar construction in which the fibrils of the core region are elongated parallel to the long axis of the grain while those of the periphery are crossed, at a low angle to the perpendicular. Presumably the heated starch molecules contract along their long axis, becoming randomly coiled, and thereby cause radial expansion in the core and axial and tangential expansion at the periphery of the starch grain.

The Tofieldieae consist of Narlhecium, Nietneria, Pleea, and Tofieldia. Although the three carpels of the pistil are generally coherent, their bases are separate for a short distance in some species of Tofieldia and in Pleea, where a septal nectary seems to be differentiated. These two genera are also alike in the extension of the chalaza as a filiform hook. The sutures are open at flowering only in some species of Tofieldia. Nietneria is distinguished by its inferior ovary and the alternate structure of the pistil. No raphide idioblasts were found in the carpels of any species.

Summary Two varieties of potato (early-maturing White Rose and late-maturing Russet Burbank) were stored at 4 and 20 °C and sampled at 15-day intervals up to 45 days after harvest. Some White Rose tubers were also stored for an extended period of over 9 months before examination. For cytological study, subsurface segments were fixed in either glutaraldehyde/ osmic acid, osmic acid alone, or KMnO 4 , then dehydrated, embedded in resin, sectioned, mounted on grids, and examined with the transmission electron microscope. A complete amyloplast membrane was present about the starch grains in all samples. The results show clearly that amyloplast membranes remain intact in cold storage.

Sweet potato (var. Jersey) and yam (var. Velvet) are ‘mealy’ and ‘soggy’ varieties, respectively, of Ipomoea batatas Poir. In the raw state the storage roots of both have virtually the same histological structure: more or less abundant starch grains in the parenchyma cells and few intercellular spaces. After baking, the sweet potato shows rounded cells which are full of gelatinised starch and are separated by numerous small, capillary-like intercellular spaces. The baked yam has very little starch, shrivelled cells, ruptured and shrunken cell walls and many large intercellular cavities. The relationships of histological structure to textural properties in these roots and in the mealy and soggy varieties of the tuber of the Irish potato are discussed.

“Sweet potato” (var. Jersey) and “Yam” (var. Garnet) are mealy (dry) and soggy (moist) varieties, respectively, of Ipomoea batatas Poir. (Convolvulaceae). The raw fleshy roots of both varieties have essentially similar quantities of all measured variables except for cellulose, hemicelluloses, and amylose. On baking, only the amounts of non-reducing sugars and possibly cellulose appear unchanged, while the reducing sugars increase markedly in both varieties, with those of the yam far exceeding those of the sweet potato. The yam's starch content (particularly the amylose fraction) falls faster and to a lower level; its water-soluble pectin content increases; and its hemicellulose content is particularly decreased. Scanning electron microscopy (SEM) showed that the cell walls of the raw fleshy roots of both varieties are coated with long parallel fibrils, 0.25–1.5 μm in diameter, which appear to be hemicellulosic. Veranderungen in der Starke und anderen Kohlenhydraten beim Verbacken von Impomoea batatas. Suskartoffeln (Var. Jersey) und Yamswurzel (Var. Garnet) sind mehlige (trockene) bzw. teigige (feuchte) Varietaten von Ipomoea batatas Poir. (Convolvulaceae). Die rohen fleischigen Wurzeln beider Arten enthalten, mit Ausnahme der fur Cellulose, Hemicellulosen und Amylose gefundenen Werte, im wesentlichen gleiche Mengen an allen ubrigen ermittelten Variablen. Beim Verbacken bleiben in beiden Arten lediglich die Mengen an nicht-reduzierenden Zuckern und moglicherweise an Cellulose unverandert, wahrend die reduzierenden Zucker merklich zunehmen, wobei die Werte bei Yam diejenigen bei der Suskartoffel erheblich ubertreffen. Der Starkegehalt bei Yam (insbesondere die Amylose-Fraktion) nimmt schneller und bis zu einem niedrigeren Gehalt ab; der Gehalt an wasserloslichem Pektin nimmt zu; der Gehalt an Hemicellulosen fallt besonders stark ab. Rasterelektronenmikroskopische Untersuchungen zeigten, das die Zellwande der rohen fleischigen Wurzeln beider Varietaten von langen parallelen Fibrillen von 0,25–1,5 μm Durchmesser, vermutlich hemicelluloseartiger Natur, uberzogen sind.

Summary Sugar content and phosphorylase activity were measured periodically in tubers of 2 varieties of potato (Solanum tuberosum: Russet Burbank and White Rose), which were stored for 45 days at 4 °C and 20 °C. At 4 °C the sucrose content of both varieties first increased, peaking at about 15-21 days, and then declined to its original level in 38-45 days. At the same temperature, the amount of reducing sugars tended to increase with time, reaching its highest level ta 21 days in the White Rose and at 45 days in the Russet Burbank. At 20 °C there was relatively little change in the content of either sucrose or reducing sugars in each variety during the storage period. The specific activity of phosphorylase from tubers of both varieties peaked at about 21-30 days at both temperatures, reaching higher values in the Russet Burbank than in the White Rose.

The effects of different anions and of solution pH on the degree of rehydration of dehydrated carrots were measured by changes in tissue volume. The carrots had significantly greater rehydrated volumes when rehydrated in distilled water than in any of the salt solutions while the carrots in salt solutions containing citrate3- had significantly lower rehydrated volumes than in the other salt solutions. This effect may be due to a steric hindrance to the penetration of the anions into the plant cells. In general, at pH values 2 and 12 the carrots rehydrated to a maximum extent. Probably the greater hydration in the solutions of extreme pH is due to their greater ability, in particular those with a pH of 12, to hydrolyse the hemicelluloses and the pectinates in the cell walls of the carrots.

The pistils of the Glorioseae (Gloriosa, Littonia, Sandersonia) are generally tricarpellate and alike. Virtually all have closed sutures at flowering; they have many ovules, some of which are barely bitegmic, with inner integuments often nearly fused with nucellar remnants; and there is usually but one compound septal bundle in the inner edge of a septum. In two species of Littonia, the compound septal bundle divided to form two simple septal bundles; but in many other plants it remained undivided, and in some it died out, still undivided, below the locular apex. Most of the placental and septal bundles are vascularized in large part by three alternate (compound septal) bundles at the base of the locules and sometimes by branches from the lateral bundles. Three large (compound) placental bundles are formed just below the lowermost ovular insertion, and each then divides in two to furnish ovular branches along their ascent. Occasional auxiliary placental bundles lie between the septal bundle and the placental bundles in the septum (Gloriosa, Sandersonia).

Chloroplasts from spinach were fixed in glutaraldehyde and extracted with three different lipid solvents, after which the lipid composition was analyzed. Studies were also made with the electron microscope. In cold dry acetone, which removes 75 % of lipids, the basic structure of the membranes is unchanged. Acetone with 10 % water removes 89 % of the lipids and a mixture of chloroform with methanol removes 93 % of the lipids, both solvents leaving nearly unrecognizable membrane structures. The relationship between lipid composition and membrane structure is discussed.

SUMMARY Cell walls of ripening fruits of peach were purified of a large part of their non-cellulosic components and examined with X-ray techniques. Small, but distinct, increases in micellar size, and perhaps in percentages of crystallinity, are a function of the maturation process. These increases are interpreted as evidence of a limited degradation of cellulose (broadly defined).

A survey of species of the prunoid genera, Maddenia and Pygeum, and of the genus Osmaronia has been made. The ovules of all are pendent, campylotropous, and epitropic. In the prunoids, the ovular supply is intimately connected with a central vascular plexus in the base of the carpel; that plexus is absent from Osmaronia. The prunoid carpels are marked by an extensive degree of fusion among the ovular and wing bundles, by fusion of the sutural margins, by fusion of the 2 integuments of the ovule to a single massive one, and by the presence of 3 or 5 well-developed bundles in the base. The carpel of Osmaronia also has a strongly fused bipartite ovular supply, separate bundles of which, however, become very much attenuated before reaching the funiculus; it has independent ovular and wing bundles, completely separate carpellary margins, 2 clearly separate integuments in the ovule, and 6 distinctive bundles in the carpel base. At the funiculus, the wing bundle of Osmaronia is connected with the adjoining weak ovular bundle by a welldeveloped vascular branch. Various particularities in the morphology of Osmaronia lend support to its segregation into a unique tribe, the Osmaronieae of Rydberg. IN CONCLUDING the comparative study of the prunoid carpel (Sterling, 1964), the author has now examined the young carpels of the 3 remaining genera commonly placed in the Prunoideae: Maddenia, Pygeurn, and Osmaronia. It should be noted that Rydberg (1918) removed Osmaronia to the separate tribe, Osmaronieae. The results of the present investigation indicate that such a segregation is justified. However, Osmaronia has been examined in this portion of the study as a concession to other taxonomic opinions, such as that of Focke (1894). A recent study (Sterling, 1963) has already shown that Prinsepia cannot be regarded as a prunoid genus. MATERIALS AND METHODS-The sources of the floral specimens were the herbaria of the University of California at Berkeley and Davis, respectively, and the herbarium of the Royal Botanic Gardens at Kew. The species used were: Maddenia himalaica Hook. f. & Thomas; M. hypoleuca Koehne; M. hypoxantha Koehne; and M. wilsonii Koehne; Pygeum fragrans Merr.; P. glandulosum Merr.; P. megaphyllum Merr.; P. preslii Merr.; P. topengii Merr.; and P. vulgare Merr.; Osmaronia cerasiformis (T. & G.) Greene. As far as possible, flowers were taken at the same stage of development, namely, unfolding of the petals. The methods of specimen preparation have been described earlier (Sterling, 1964). RESULTS-Maddenia-According to Focke (1894), the genus is dioecious, and the pistillate flowers are bicarpellate. However, Koehne (1911) found that in the Chinese species, at least, the I Received for publication July 19, 1963. This investigation was aided by funds from the National Science Foundation, given under grant G-16142. The microtechnical work was performed by Dr. Maxine Thompson. It is a pleasure to thank both the Foundation and Dr. Thompson for their help. flowers are perfect and monocarpellate. The writer has examined all the specimens of Maddenia in the herbaria of the University of California at Berkeley and the Royal Botanic Gardens at Kew, with the same results: all species, including M. himalaica, have perfect flowers that are predominantly monocarpellate. Each carpel has 2 monotegmic ovules which are pendent, campylotropous, and epitropic. The carpellary margins are fused throughout the length of the ovary. Although the commissural suture is marked externally by a slight cleft along the ventral surface of the ovary, internally the ventral ovarian surface is smooth from the base of the locule up to the level of ovular attachment. Upwards from this level to the top of the locule, a linear groove is evident on the internal ventral surface. (This groove is fairly deep in M. hypoleuca.) A short distance above the insertion of the staminal traces, the center of the vascular cylinder is occupied by a sparse vascular plexus (Fig. 1, 2). At flowering, that plexus is still procambial. The vascular cylinder that supplies the carpel may be composed of 5 main bundles (M. himalaica, M. hypoleuca), or only of 3 large bundles (M. hypoxantha, M. wilsonii). When 5 bundles are present they are the dorsal bundle, 2 wing bundles, and 2 inner vegetative bundles next to the ovular supply.2 The bipartite ovular supply lies between the wing bundles, close to the sagittal plane. Xylem and phloem in the dorsal, wing, and inner vegetative bundles are radially collateral. However, in the ovular supply the xylem and phloem are almost tangentially collateral at the sagittal plane, with the phloem of each half directed toward the phloem of the other. These phloic 2The terminology used here has been explained by Sterling (1964).

Embryos of Larix decidua were placed on synthetic culture media at the stage at which the primary suspensors (and occasionally also the first embryonal tubes) were elongating. Usually several additional cells, destined to form embryonal tubes, were also present behind the apical embryonic tier. After 2 months, growth in the forty different media was limited in comparison with that in natural conditions. Not all embryos grew uniformly, and the type of growth was anomalous. In several cases cleavage of the first embryonal tubes occurred at the tips of the primary suspensors. The significance of this "abnormal" cleavage in the larch embryo is discussed.

Viscosity parameters were obtained for maize maylose (molecular weight of 107,000) in 1N KOH at 25, 30, 35, and 40°C. Intrinsic viscosity continuously decreased and Huggins' constant k' continuously increased with increasing temperature. The temperature dependence of intrinsic viscosity, d[η]/dT, was −2.12 × 10−2/°C.

SUMMARY Blanched and unblanched dice of carrot phloem were dehydrated at two different rates and stored for periods up to 6 months. The rehydrated volume was always greater for blanched dice than for unblanched. In all samples, the rehydrated volume decreased as a result of storage. No consistent differences among samples could be attributed to differences in rate of dehydration. Cellulose, extracted from the dice, was examined for crystalline content by water-vapor sorption, X-ray diffraction, iodine adsorption, enzymatic digestibility, and density methods. All methods agreed in showing a higher crystallinity in unblanched than in blanched samples, a continual increase in crystallinity in all samples as storage time increased, and no notable differences in crystallinity as a result of different dehydration rates.

SUMMARY An X-ray diffraction study was made of several plastic fats, including lard, butterfat, oleomargarine, and hydrogenated vegetable shortenings. Their liquid contents were varied by altering the holding temperature. Separate mixtures were made of cocoa butter or tristearin with corn oil, tributyrin, or trioctanoin, and their diffraction patterns were obtained. The crystal form (omega), previously described for oxidized cocoa butter, was found in the first group of fats and in the corn oil-tristearin mixture. Omega crystallinity was not related to the solid-liquid ratio of the fats or to differences in molecular length in the constituent fatty acid radicals. Omega crystallinity seemed to be related to a general difficulty in crystallization, probably due to steric hindrances.

Freshly isolated spinach (Spinacea oleracea) chloroplasts were treated with 4 different neutral salt solutions at concentrations of 1 and 2 M for ultrastructural study. Each salt induces a specific pattern of structural disorganization. In KCl, there is principally swelling of the fret-canal and end-granal-compartment loculi. With KI, there is removal of green pigment, loss of some stainability, swelling, and separation of the individual membranes of the granal partition layers. Sodium trichloracetate causes apparent end-to-end fusion of granal stacks and their curvature; and in KSCN there is a great volume increase, related to the separation of the membranes of the partition region and extensive swelling of all the loculi. This work has been rendered possible through a grant from the National Science Foundation (GB 12906).

The carpels of 2 groups of pomoid genera, Amelanchier, Malacomeles, Peraphyllum and Aronia, Malus, Pyrus, and Sorbus, were analyzed morphologically. Open sutures are associated with a lesser extent of tegumentary fusion and ovular bundle-wing bundle fusion than are closed sutures. However, in the genera as a whole (and particularly in Aronia and Sorbus), the extent of sutural closure is inversely related with the amount of intercarpellary adhesion and with the fusion of carpels to the floral cup. In the Amelanchier group and in Malus and Pyrus, ovularand wingbundle fusion is directly related with intercarpellary adhesion. Malus and Pyrus have closer structural resemblances with one another than they have with Aronia and Sorbus.

DESPITE THE great wealth of botanical literature concerned with the initiation of adventitious buds (Priestley and Swingle, 1929; Buvat, 1944-45; Peeters, 1947), there have been relatively few anatomical studies on bud initiation in tissues cultured in synthetic media. Buvat (1944-45) has summarized these and has, himself, added considerably to an understanding of the problem of "dedifferentiation"2 of plant cells. However, his investigations concern principally the cytological aspects of primordium formation. Although Camus (1949) has studied the changes in subjacent tissues during bud development, he has not considered the details of initiation of the shoot primordia. Previous communications (Skoog, 1944; Skoog and Tsui, 1948, 1951; Sterling, 1950) have shown a marked correlation between relatively high levels of adenine, supplied through a culture medium, and bud initiation in tobacco stem segments. Obviously, the establishment of such a relationship makes possible the chemical control of bud formation. It is, therefore, of interest to place on record the successive steps in this controlled initiation of shoot primordia in vitro. This paper presents an anatomical description of such development and considers the latter in relation to the general problems of meristematic activity and dedifferentiation. MATERIALS AND METHODS.-The materials and methods used are those reported earlier (Sterling, 1950), with the limitation that this account deals only with the tobacco stem segments which received adenine sulfate (40 mg./l.) in the basal medium. The material is representative of the samples used in physiological studies on growth and tissue composition. Segments grown on control media were described in the earlier paper. SITES OF BUD ORIGIN.-In these cultures, there are three maj or regions of bud formation, Viz., cambium-external phloem, internal phloem, and callus. The region of the cambium and its young phloic derivatives produces the maj ority of bud primordia. In most instances, no sharp distinction can be made between these two classes of cells in the rapidly dividing cambial zone; therefore, this source of buds was previously reported as cambial (Sterling, 1950). However, in some cases bud primordia are found exclusively in the external phloem, with differentiated sieve tubes lying be

Various starch materials and cotton cellulose were deuterated in liquid deuterium oxide. Relative accessibility (amorphous content) was determined by infrared spectroscopy. The values obtained agreed on the whole with those determined by X-ray diffraction methods. In all cases, there was a residuum of inaccessible (usually crystalline) material which could not be deuterated.

The two genera of Buxbaum's tribe Wurmbaeae, Anguillaria and Wurmbea, have multiovulate carpels. There are deep septal indentations between the carpels of Anguillaria, but the wings of adjoining carpels are fused to solid septa in most species of Wurmbea. In Anguillaria the carpels have open sutures or prominent commissural markings; in Wurmbea the carpels generally lack these characteristics, and some species have a vascularized, columella-like axis in the centre of the pistil. In both genera there are a dorsal bundle, lateral bundles, and two placental bundles in each carpel. At the inner edge of the septum there are one or two septal bundles in Anguillaria and one or none in Wurmbea. The ovules are monotegmic, the integument and funiculus being partly fused in Anguillaria and mostly fused in Wurmbea. An obturator is present in Anguillaria but absent from most species of Wurmbea.

SUMMARY The submicroscopic structure of the starch grains of Zea mays and Triticum sativum was studied electron-optically from replicas made of internal, fracture surfaces. In corn starch, long cylindrical microfibrils were found, arranged in a radial direction and imbedded in an amorphous matrix. Their diameter was uniformly about 200 A. Microfibrils were also indicated in wheat starch because of the prominence of their ends in surface view. Many microfibrils in corn starch appeared to be helically coiled. The more ordered starch substance was presumed to be localized principally in the microfibrils.

The pistil of Androcymbium closely resembles that of Colchicum: it is tricarpellate usually, syncarpous and multiovulate, and the carpels of most species have open sutures and bitegmic ovules. The only species with closed carpellary sutures, A. dregei has monotegmic ovules. There are always three dorsal bundles and three compound septal bundles, which latter may bifurcate into simple septal bundles. Six placental bundles (two per carpel) are differentiated, either separately from the compound septal bundles or as lateral branches of them. A statistical evaluation of 47 species (6 genera) of the hemisyncarpous Wurmbaeoideae shows a significant tendency for bitegmic ovules and two simple septal bundles per septum to be associated with open sutures and for monotegmic ovules and no septal bundles to be associated with closed sutures.

The multi-ovulate pomoids, Chaenomeles, Cydonia, and Docynia, all have closed sutures and extensive fusion between carpel and floral cup and between ovular and wing bundles. Although the ovules in Docynia are generally apotropic and few in number (4-7), the ovules in the other two genera are pleurotropic and numerous (15-48). A statistical treatment of the whole tribe of Pomoideae shows that in carpels with open sutures ovular and wing bundles definitely tend to be separate while in those with closed sutures these bundles tend to be fused. To a lesser degree carpels with open sutures also tend to have bitegmic ovules, separate carpels, and a lesser extent of fusion between carpel and floral cup, while carpels with closed sutures tend to have monotegmic ovules, united carpels, and a greater extent of fusion between carpel and floral cup. THE POMOID genera, Chaenomeles, Cydonia, and Docynia, have multi-ovulate carpels. In 1906 Schneider described the genus Pseudocydonia. Weber (1964) believed, however, that this taxon is really Cydonia and that Pseudocydonia sinensis Schneid. is more properly named Cydonia sinensis (Dum.-Cours.) Thouin. If it be considered that the multi-ovulate condition is atavistic (Bailey and Swamy, 1951; Eames, 1961), the carpels in this group could be expected to show other primitive features. It is with considerable interest, then, that an analysis of the multi-ovulate genera has been undertaken. MATERIALS AND METHODS-Flowers for this study were generously provided by the Miorris Arboretum, the Arnold Arboretum, the U. S. National Herbarium, the Harvard University Herbarium, and the herbaria of the Natural History Museum of Vienna, the University of Vienna, and the University of California (Davis, Berkeley). The species studied, with the number of samples indicated in parentheses, incluide Chaenomeles cathayensis (Hemsl.) Rehd. (1), C. japonica (Thunb.) Lindl. (3), C. speciosa (Sweet) Nakai [C. lagenaria (Loisel) Koidzuml (2); Cydonia japonica Lindl. (2), C. oblonga Mill. (2), C. sinensis (Dum.-Cours.) Thouin (6), C. vularis Pers. (4); Docynia delavayi Schneid. (2), D. docynoides (Schneid.) Rehd. (2), D. indica Decne. (2), D. rufifolia (Ldveill6) Rehd. (1). Specimens were prepared in the manner previously described (Sterling, 1964a). As in previous studies (see Sterling, 1964c) the observer follows the course of the vascular bundles, as they appear to ascend from the receptacle. No ontogenetic movements are implied in the de'Received for-publication February 9, 1965. This study wasi supported by grant G-16142 fr om the National Science Foundation and by a fellowship grant t_ _-,_h Tr_hr_ CMna_ 17_1-___1nhoim V_-_AlW ilfSi.ir4scriptive terminology, which has been chosen mainly for convenience. RESULTS-Chaenomeles-A set of dorsal collateral bundles, equal in number to the number of carpels (4-5), is separated from the gynoecial cylinder in the receptacle. The remaining bundles of the cylinder, which are normally oriented, lie grouped closely together in a like number of arcs. These arcs are convex centripetally at the base of the locules and alternate with the locules and the dorsal bundles (Fig. 1). The arcs become Vshaped higher up, with the vertices directed centripetally. Each divides radially at the vertex of the V. The division takes place just below the locule in C. cathayensis and above the locular base but below the lowermost insertion region in the other two species. Two large ventral bundles are thus formed, each supplying one of two adjoining carpels above and furnishing branches to the ovules. With reference to the receptacle, the ventral bundle has centripetal xylem and centrifugal phloem when first delimited. Below the lowermost insertion region in C. cathayensis, but above this region in the other two species, the ventral bundle rotates and becomes V-shaped with the vertex centripetal. It then divides radially into a wing bundle that lies near the carpel margin and a large ovular bundle complex near the suture (Fig. 3). These bundle groups are oriented so that the median longitudinal planes of the two derivatives are near-tangential, the phloem of the wing bundle facing the lateral carpellary margin and the phloem of the ovular bundle complex facing the suture. The ovu]ar bundle complex consists of two or three nearly distinct bundles, the innermost one (i.e., closest to the funiculi) giving rise to a branch to each ovule along a carpellary margin. Along its upper course the ovular bundle complex becomes more and more attenuated. It disannears

A B S T R A C T A comparative study of carpellary structure in the spiraeoid subtribes Quillajeae and Sorbarieae has shown that morphological inter-relationships are similar to those of other Rosaceae. When the suture is closed the carpels tend to be coherent and the ovular and wing bundles tend to be fused. These relationships are statistically significant in the Spiraeo deae as a whole. The construction of the gynoecium in Lindleya and in most species of Vauquelinia resembles that of a pomoid. Other features of a pomoid-spiraeoid affinity have been discussed. sub-tribes of the Spiraeoideae: Holodisceae, Neillieae, Spiraeeae, and Ulmarieae. The present study deals with the two remaining sub-tribes of this group: Quillajeae and Sorbarieae. Both Maximowicz (1879) and Jue (1918) regarded the Quillajeae as the most primitive sub-tribe of the Spiraeoideae. On the basis of the vascular structure of the pedicels and carpels, Bonne (1928) agreed with this view and declared that the other groups in the Rosaceae could be considered to diverge from the

This preliminary study has related the nature of rupture in starch grains, induced by ultrasound, to the ambient atmosphere, the concentration of the suspension, the frequency and the time of irradiation. It has been tentatively concluded that principally mechanical effects have been induced under conditions that would promote vaporous cavitation (280 KHz, 15 W/cm2). In an atmosphere of hydrogen, many deep conical pits are produced. In an atmosphere of air or oxygen, deep pitting is somewhat less pronounced than in hydrogen but injury to other parts of the surface is greater. Virtually no effect is produced in vacuo, and under carbon dioxide the effect is very weak. The extent of damage increases with time of radiation and decreases with increasing concentration of starch in the suspension. It is suggested that damage produced by ultrasound indicates a primarily radial structure of submicroscopic units in the starch grain. Explanations proposed for the effects observed must be tested in further experiments.

Summary X-ray diffraction patterns were obtained from fresh and frozen aqueous gels of agar, carboxymethyl cellulose, gelatin, and starch. Radial distribution functions, based on an averaged nonhydrogen atom of the 10% gel of each, indicated a closer nearest neighbor spacing of the atoms in gels of agar and carboxymethyl cellulose than in water or gels of the other two polymers. The X-ray diffraction pattern of the frozen gel was that of hexagonal ice at low concentrations of polymer, near cubic at intermediate to high concentrations, and vitreous at high concentrations. The near cubic and vitreous patterns are explained on the basis of the size of the subcrystalline grouping of water molecules.

Elongated acicular and tabular crystals have been found in the laticiferous cells ofAllium cepa (var. “Yellow Globe”). Although these show predominantly lipoidal properties, a possible proteinaceous relationship has been discussed.

By being brought to the threshold of gelatinization through careful heating in water, grains of native potato starch often were induced to swell differentially. At 55°C, radial elements (sectors) of the interior of these grains contracted centrifugally and expanded tangentially while the rigid exterior remained mostly unswollen and therefore was burst open due to the swelling of the interior. Evidence from the light microscope, the polarizing microscope, and the scanning electron microscope showed clearly the presence of radially oriented and near radial, crossed fibrillar elements, each of which traversed many lamellae, in the ungelatinized region. No ‘core’ was evident in the burst starch grain, nor was there any separation of lamellae.