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THREE distinct classes of phage-specific proteins—“pre-early”, “early” and “late”—are synthesised in a temporal sequence after infection of Escherichia coli with bacteriophage T51(Fig. 2a). The synthesis of pre-early proteins begins within the first minute after infection and is shut off 8–10 min later1,2. The beginning of synthesis of early proteins is delayed until about 6 min after infection. This delay is mechanical, and is a result of the transfer of phage DNA to the host cell in two steps1,3. The rate of synthesis of early proteins decreases considerably after 20 to 25 min of infection, but synthesis does continue through the late period at diminishing rates. We have observed that the rate of synthesis of most early proteins is diminished normally even when the turn-on of synthesis of late proteins is defective4. This observation suggested to us the presence of a negative control mechanism for the ‘shut-off’ of synthesis of early proteins, rather than a passive shut-off, such as a competition between early and late transcripts for the translational system of the infected cell. We have identified a gene the product of which is required for the shut-off of synthesis of phage specific early proteins, but which is also required for the replication of phage DNA.

The article considers the use of computational fluid dynamics (CFD) for simulating clarifier performance. Considered an innovative technique for clarifier design, troubleshooting and optimization, CFD utilizes mathematical models for analyzing systems that involve fluid motion, mass transfer, heat transfer and associated phenomena, like chemical and biological reactions. CFD models can be utilized for determining improvements to existing clarifier infrastructure that increase clarifier performance and capacity. These models should be used cautiously and with a good understanding of the processes and factors that affect clarifier performance.

The DNA molecular weights were determined by calibrated electron microscopy. The results (in units of 106) are: for T5, 77.4 ± 2.4; T5st(0), 72.4 ± 1.9; BF23, 76.7 ± 2.3; and BF23st(4), 71.4 ± 1.7.

Abstract Interspecific nest sharing between 2 species of sphecid wasps is recorded for the first time. A nest of Cerceris antipodesSmith appeared to have been joined by a female of C. australisSaussure. The nest contained 2 cells with a mixture of prey of both species, 26 older cells with C. antipodesprey and 6 younger cells with C. australisprey.

The article features several exhibitions in Great Britain. J.M.W. Turner's paintings are exhibited at the Royal Academy until March 2, 1975. The exhibition "English influences on Vincent van Gogh," organized by Ronald Pickvance, at Nottingham University. The exhibition "Hampstead in the Thirties" is on view at the Camden Arts Centre until January 19, 1975.

MY brother, the late Lieut. R. H. McCorquodale, of the 3rd Dragoon Guards, while doing special service duty in West Africa, was fortunate enough to kill a very fine giraffe (female). This is a most interesting record, as it is the only specimen that has ever been obtained in these regions. The skull, which was sent home to me, along with a considerable number of heads of antelope, lion, leopard, &c, is now in the British Museum, and Mr. Oldfield Thomas, of that institution, has compared it with the skulls of both the Northern and Southern forms; such marked differences have been noticed, that opinion is in favour of the possibility of its being a new species—for the time being, until it has been more fully worked out, he has made it a special sub-species, and named it Giraffa camelopardalis peralta. The giraffe was killed south of the Benue River, north of Calabar. The accompanying map will roughly show the geographical distribution of the two known forms, the haunts of these animals being filled in. Although one or two specimens have been recorded on the eastern shores of Lake Chad, and also on the Senegal River, from 10° N. to 20° S. of the equator no fact is on record of a giraffe having been seen or killed within the degrees mentioned in all that part designated West Africa. The map will show at a glance the immense tracts of country between the habitats of these animals and the spot where this single animal was killed. In a letter I had from Sir George Taubman Goldie, the Governor of the Niger Company, he says: “This is the only giraffe ever known in these regions; I have no doubt there are others, but they have never been seen.”

IN the course of an investigation into the distribution of water-soluble carbohydrates in seeds of the Gramineae1, it was observed that two species of grass (Lolium perenne L. and Festuca pratensis Huds.) contained in their caryopses substantial amounts of a trisaccharide which was not detected in any of the thirty other wild grasses and cereals examined. This non-reducing trisaccharide (Fig. 1, X) had a specific rotation of + 90.5° (without recrystallization), yielded equal amounts of galactose, glucose and fructose on acid hydrolysis and was readily broken down to fructose and a reducing disaccharide in the presence of invertase or very dilute acid. This ease of hydrolysis suggests that the trisaccharide resembles raffinose in containing a terminal β-fructofuranoside residue. Iodine oxidation2indicated that the galactose residue was at the non-reducing end of the disaccharide, and electrophoretic mobility of the disaccharide in borate was intermediate between the mobilities of laminari-biose and melibiose. Movement in borate is allied to the mode of linkage of sugar residues3, disaccharides containing 1,2 or 1,4 linkages being of much lower mobility than those containing 1,3 or 1,6 linkages. The disaccharide under consideration would therefore appear to contain either a 1,3 or a 1,6 linkage. Although the electrophoretic behaviour in borate does not distinguish between α and β linkages, the high positive rotation of the trisaccharide suggests that the galactose and glucose residues are α-linked, and, since 6-glucose-α-galactoside is melibiose, it seems probable that the newly isolated disaccharide is 3-glucose-α-galactoside. The trisaccharide from Lolium perenne and Festuca pratensis is therefore tentatively described as α-D-galactopyranosyl-3-α-D-glucopyranosy 1-2- β-D- fructofuranoside.

SOME few months ago I received a consignment of skulls of antelopes from West Africa, the specimens having been shot by the late Lieut. R. H. McCorquodale, 3rd Dragoon Guards, and on opening the cases I was much struck by the appearance of the horns; all, without exception, were infested by singular thin finger-like protuberances which seemed to grow from the horn, leading me at a first impression to the immediate conclusion that they were some species of fungi; on a nearer inspection I found them to be cocoons, and not having seen anything like them before I looked into what literature I could find on the subject.