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During the last three years of this period the writer has spent some weeks of each year observing and collecting Myriapoda at various camps and outposts so that the total area of the Park has been fairly completely covered, though not in great detail. The faunal list provided in this paper, though it can by no means be claimed to be comprehensive, does give a fairly accurate approximation of the families and genera which can be expected to occur within the boundaries of the Kruger National Park; it is at the same time the first systematic survey of any subregion of the Transvaal Province.

The synthesis of a diastereomerically pure 10-hydroxywarfarin [4-hydroxy-3-(2-hydroxy-3-oxo-1-phenylbutyl)-2H-1 benzopyran-2-one] was accomplished in three steps from racemic warfarin. The relative configuration of the synthetic product was established by conversion to a cyclic derivative followed by NMR and X-ray diffraction analysis. Absolute stereochemistry was determined by enzymatic conversion of either of the pure enantiomers of warfarin to a 10-hydroxy metabolite of known relative configuration. Metabolic formation of 10-hydroxywarfarin was studied using hepatic microsomal preparations from female rats and man. The formation of 10-hydroxywarfarin catalyzed by hepatic microsomes from both dexamethasone-treated rats and man was highly stereoselective [(R)/(S): 3.4-9.0] for (R)-warfarin. In contrast, little stereoselectivity was observed in reactions catalyzed by untreated rat liver microsomes. The resultant stereochemistry at the site of oxidation was also found to be highly dependent on substrate stereochemistry. (R)-Warfarin gave (9R;10S)-10-hydroxywarfarin with only a trace of the (9R;10R) isomer irrespective of which enzyme preparation was used for catalysis, while (S)-warfarin gave (9S;10R)-10-hydroxywarfarin with only a trace of the (9S;10S) isomer, again irrespective of which enzyme preparation was used for catalysis.

Previous kinetic studies have identified a high-affinity (S)-warfarin 7-hydroxylase present in human liver microsomes which appears to be responsible for the termination of warfarin's biological activity. Inhibition of the formation of (S)-7-hydroxywarfarin, the inactive, major metabolite of racemic warfarin in humans, is known to be the cause of several of the drug interactions experienced clinically upon coadministration of warfarin with other therapeutic agents. In order to identify the specific form(s) of human liver cytochrome P-450 involved in this particular toxicity, we have determined the metabolic profiles of 11 human cytochrome P-450 forms expressed in HepG2 cells toward both (R)- and (S)-warfarin. Of the 11 forms examined only 2C9 displayed the regioselectivity and stereoselectivity appropriate for the high-affinity human liver microsomal (S)-7-hydroxylase. We further compared Michaelis-Menten and sulfaphenazole inhibition constants for (S)-warfarin 7-hydroxylation catalyzed by cDNA-expressed 2C9 and by human liver microsomes. Similar kinetic constants were obtained for each enzyme source. It is concluded that 2C9 is likely to be a principal form of human liver P-450 which modulates the in vivo anticoagulant activity of the drug. It is further concluded that those drug interactions with warfarin that arise as a result of decreased clearance of the biologically more potent S-enantiomer may have as their common basis the inhibition of P-450 2C9.

Power rectifiers have proved themselves as efficient and reliable converters of a-c to d-c power for many industrial applications. They also have been used to a limited extent as exciters for synchronous motors and condensers. This paper discusses the requirements of rectifiers when used to excite large a-c generators and presents the results of tests made to determine performance under various operating conditions. The results cover preliminary tests that were made on a laboratory model in addition to extensive and more complete tests on an electronic exciter now installed in the Springdale generating station of the West Penn Power Company. The electronic exciter was designed to serve eventually as the main exciter for an 81,250-kva 3,600-rpm turbine generator just installed, but it is now supplying excitation to a 47,100-kva 1,800-rpm turbine generator. Switching arrangements are provided for exciting either unit from the electronic exciter or from an existing motor-driven exciter.

Two species and one subspecies of the family Solpugidae are described as new, viz. Zeriassa luxeni and Solpuga strepsiceros nocturnus from the Kruger National Park, E. Transvaal, Solpugema broadleyi from Southern Rhodesia. Three new species of the family Daesiidae are also described, two, Broomiella browni and Hemiblossia termitophila, from South West Africa, one, Blossiola singularis, from the Kruger National Park. A supplementary description is given of the two sexes of Solpuga celeripes Hirst, described in 1911 from Salisbury, Southern Rhodesia.

Summary The external structure of the cleaning organ or brush situated on the tarsus of the pedipalp in the Amblypygi has been examined in the following six species from tropical and southern Africa: Damon variegatus (Perty) Damon medius (Herbst), Titanodamon johnstoni Pocock, Phrynichus scullyi Purcell, Phrynichus bacillifer (Gerst.) and Hemiphrynus machadoi Fage. In all except one of these species the organ consists of two approximately parallel rows of modified setae; in Hemiphrynus machadoi there is only one. When both rows are present the constituent setae of each are quite different in appearance and structure. It is probable that the variations in number, size and shape of the setae in these forms furnish specific characters; further indirect support for this is afforded by the marked difference in the structure of the organ in Hemiphrynus as compared with the other five species; taxonomically Hemiphrynus belongs to the subfamily Tarantulinae while all the others are accommodated in the Phrynicinae or Damoninae. A brush-like cleaning organ of some kind is found on the pedipalp-tarsus of both old and new world Amblypygi and most probably in all members of the order.

Two new species of scale-mites (Pterygosomidae) are described from lizard hosts, and the male of a third species, previously known from females only. A new Listrophorid mite, from the Cape Horseshoe bat, is also described.

Some years ago the South African Museum received a tube of mites taken from the South African scaly anteater, Smutsia temmincki, by Dr R. Bigalke, Director of the National Zoological Gardens at Pretoria. The tube contained more than 200 well-preserved gamasid mites, and I wish to express my thanks to Dr Bigalke and the authorities of the South African Museum for affording me this opportunity of studying these parasites.

A new species of Biton from the Kalahari is described. Some observations are made on the ctenidial hairs and the tarsal spines of Biton schreineri (Purcell) and its relationship with Broomiella lineata (Pocock). Comments are made on the distribution of Solpuga monteiroi Pocock and the systematic position of ‘Solpuga grindleyi n. sp.’ Brown.

(1955). A New Mange-Mite from the Cape Polecat. Annals of Tropical Medicine & Parasitology: Vol. 49, No. 1, pp. 54-62.

In a previous paper (1935) an account was given of the prostigmatic mites parasitic on South African lizards, belonging to the two endemic families, the Zonuridae and Gerrhosauridae. The present paper deals with the fauna of the two remaining families of lizards, the Geckonidae and Agamidae, parasitised exclusively by prostigmatic mites. Trägardh (1905) and Hirst (1926) have made the most considerable contributions to the knowledge of the parasites of Geckonid and Agamid lizards; the latter placed the group on a sound systematic basis, the former, in addition to his descriptions of new forms, contributed valuable notes on the development and morphology of the species studied. With regard to mite parasites, however, up to the present, no systematic investigation has been attempted of all the species belonging to any one family of lizards from a given zoo-geographical region. In the present paper this has been attempted; the great majority of Geckonid and all the species of Agamid lizards from the South African subregion, either as living or spirit specimens, have been examined; from most of them mite parasites have been obtained. Both families of lizards are, genealogically speaking, derived from a long-established, Saurian stock; both are, in South Africa, extremely well demarcated, homogeneous families, with their main structural characteristics varying within narrow limits. In neither of them does loss or degeneration of the limbs occur. Each family is parasitised by a single genus of prostigmatic mites, the Geckonidae by Geckobia, the Agamidae by Pterygosoma; while Geckobia is found on the Geckonidae and on no other family, Pterygosoma is also a parasite of Gerrhosaurid lizards on which three species have been found. In a previous paper by the writer (1935, p. 3) Pimeliaphilus was cited as occurring on Geckonidae. Trägardh, who erected the genus (1905, p. 31), actually found his species P. podapolipophagus living under the elytra of a beetle, Pimelia, but the other two species of the genus, P. insignis Berl. and P. tenuipes Hirst, both occur on Geckonid lizards. Neither of these two species have been found in South Africa and it is extremely unlikely that they occur in this region.

(1943). NEW SOUTH AFRICAN MITES OF THE GENUS TENUI-PALPUS DONNADIEU (TETRANYCHIDAE) Transactions of the Royal Society of South Africa: Vol. 30, No. 1, pp. 35-48.

Summary The comb-like cleaning organ on the movable digit of the chelicera in the short-tailed whip-scorpions (Schizomida) is compared with that found in Pseudoscorpions and the Amblypygi. It does not occur on the chelicera of the long tailed whip-scorpions (Uropygi). The various trichoid structures on the immovable digit of the chelicera of the Schizomida, nearly all on its inner surface, are enumerated and described; some of them are compared with similar structures in the Pseudoscorpions, Solifugae and Ricinulei.

THE adoption of higher secondary voltages in commercial areas1 involves the careful consideration of suitable voltage spreads and the corresponding plausible voltage levels for supplying utilization equipment. There is urgent need for the industry to select a level that will be generally suitable and acceptable in order to avoid a variety of voltages in various parts of the country and the corresponding variety of equipment ratings.

Summary. Certain features of the first larval stage of the South African Solifuge, Solpuga hostilis White, are described. The newly hatched larva is provided dorsally with a number of long and very stout brownish setae arranged serially in symmetrical pairs on the head, thoracic and abdominal regions of the body; in the larva which has just been released from the egg, they are folded in a characteristic manner, forming a pattern which is the same in all the larvae. The setae are quite different from the long delicate hairs and setae of the adult Solpuga, being very much longer and thicker in proportion to the body length. Before the rupture of the egg capsule, the eggs show a number of dark lines and markings, forming a pattern which is uniform in a series of 61 eggs. This pattern has nothing to do with the covering of the egg itself but is caused by the dark setae showing through the semi-transparent capsule, some of them lying side by side to form fairly broad bands. The prominent larval setae of Solpuga hostilis are certainly not found in the newly hatched larva of Galeodes (araneoides and caspius), the only other Solifugae in which this stage of development has been described; such large setae are very unusual in the newly hatched stages of Arachnida and Myriopoda where the delicate and soft-skinned larva on emerging from the egg is nearly always devoid of hairs, spines or other cuticular out-growths. The claws of the appendages and the external appearance of the lateral organ are compared with these structures in Galeodes at the same stage of development.

The purpose of this paper is to present a method for the determination of inductive and capacitive unbalance for untransposed transmission lines. To accomplish this purpose, the conventional methods of symmetrical components are used. It is shown that the negative and zero-sequence currents in an untransposed line are functions of the positive-sequence load current, charging current, and line configuration. Calculated values of negative- and zero-sequence currents for typical configurations of high-voltage transmission lines are presented.

The parasites described in this paper were taken from twelve specimens of the Natal horseshoe bat (Rhinolophus geoffroyi zuluensis) found in a cave near Wartburg, Natal, in May 1937. Thirteen specimens of the parasite were taken from the vibrissae situated on or near the nose-leaf of the host, each of them being attached near the base of one of these tactile hairs. No single vibrissa was found to have more than one parasite attached to it. The largest number of mites taken from any one host animal was four, the smallest was one, and none were found on any part of the body other than the facial region. With the aid of a hand lens the parasites can easily be seen clinging to the nasal vibrissae, where they appear as minute white specks. So far as I am aware mites of the family Listrophoridae have not previously been described or recorded from South Africa.