ALBERT

Description: Distributions of the species of Foraminifera (living and dead) forming the greater part of the foraminiferal faunas in marshes in Poponesset Bay, Massa- chusetts, have been studied. Eight stations were sampled bimonthly for one year (August, 1956 to September, 1957). The marsh environments vary from almost non-marine (with tidal influence) to near marine. Arenoparrella mexicana, Haplo- phragmoides hancocki, Tiphotrocha comprimata, and Trochammina macrescens de- crease with increasingly marine conditions, whereas Jadammina polystoma and Trochammina inflata increase. Other species such as Ammobaculites dilatatus, Am- motium salsum, Miliammina fusca, and Protelphidium tisburyense fluctuate inde- pendently of the degree of brackish or marine conditions. Unknown factors govern- ing micro- and macroenvironments probably play an important part in controlling distributions. Suggested factors are type of vegetation, chemical factors, pH, nutrients and food. Calcareous specimens are rapidly destroyed after death pre- sumably due either to the ability of the living form to resist acidity or to a postu- lated increase in acidity immediately below the sediment surface, more probably the latter. This destruction of the tests is of importance in the interpretation of ancient marsh environments. Many species, including the calcareous ones, had their largest living populations in June or September and their smallest in December or February. There were some exceptions such as Miliammina fusca which showed an increase in winter. The total living populations were greatest in June and lowest in December, which may be related to maximum temperature and time of greatest reduction in temperature respectively. Multiple sampling showed that distribu- tions at any one station were fairly uniform although nearby samples in different microenvironments in some cases vary considerably.

Description: The results show that liquid fertilizers generally gave lower yields of dry matter than conventional solid fertilizers in four experiments on grassland. In seven trials, on autumn wheat, spring wheat, sugar beet and kale, the efficiencies of the two forms of fertilizer were similar.Liquid fertilizers containing ammonia must be injected into the soil and this needs special equipment, more complicated, particularly where anhydrous ammonia is to be used, than the distributors used for solid fertilizers. Running the injector over established grassland sometimes resulted in considerable damage to the sward. When used to top-dress winter wheat across the line of drilling some plants were killed.

Description: 1. The problem of inbreeding and the fixation of apparent heterosis in the cultivated tomato and in inbreeding crop species generally is discussed. The case is argued that ‘heterosis’ as normally understood in out-breeders is not likely to exist as a general phenomenon in inbreeding species.2. Selections were made among segregating progenies of two successful, commercial F1 hybrids, and the performance of the selected lines, up to the F4 generation, shows that the superiority of the hybrids over their parents can be fixed in purebreeding lines.3. Owing to selection effects in inbreeding species of crops the best parents will differ in respect of fewer quantitative loci than is to be expected from general experiments on quantitative inheritance. In the present material, desirable recombinants were isolated at a frequency of 1 in every 1000–1500 F2 individuals.4. The utility of F1 hybrids in the tomato thus depends on the economy of effort involved in their development as compared with the isolation of pure lines. It is concluded that the production of hybrids is to be favoured only when reliable methods of prediction of their performance are available, and then as an interim measure while pure-line forms become available.

Description: In recent investigations at this Institute, attempts have been made to devise for dairy cows a ration extremely low in magnesium to be used in fundamental studies of magnesium metabolism. All common farm roughages are moderately rich in magnesium, and wood pulp, which is low in this element, has been tested as a roughage for use in these experimental rations. American workers (Titus, 1926; Mead & Goss, 1935; Byers, Stanbus, Nelson, Brown, Davis & Gardiner, 1955; Matrone, Ramsey & Wise, 1957; Smith, McLaren, Anderson, Welch & Campbell, 1957; Ellis & Pfander, 1958; Williams, Musgrave, Schul & MacVicar, 1958) have previously used wood pulp as a substitute for roughage in the development of purified rations for cattle and sheep, and it was fed extensively as a substitute farm feedingstuff in Norway during the war years (1940–44)(Edin, Helleday & Nordfelt, 1941; Hvidsten, 1946). This note records some observations on the feeding of wood pulp, often as the sole roughage, to both dry and milking cows.

Description: 1. A 3-year experiment is described in which perennial rye-grass/white clover swards were cut to within either 1 in. of 2–2½ in. of ground level when the herbage had reached either the ‘grazing’ or the ‘silage’ stage of growth. Superimposed on the cutting treatments were several fertilizer treatments which involved application of varying amounts of nitrogen at different dates over the season.2. Throughout the experiment cutting to within 1 in. of ground level gave greater dry-matter and crude-protein yields of mixed herbage and of clover than cutting to within 2–2½ in. of ground level, the increase in dry-matter yield ranging from 39 to 49%.3. The response of clover to these ‘height of cutting’ treatments developed more slowly than the response of the sward as a whole, and was modified in the later stages by the particular fertilizer nitrogen treatment applied.4. It is suggested that the greater herbage yields obtained from close- than from lax-cut swards resulted from the differential effects of the two cutting treatments on stem and leaf formation in the grasses, but the need for further investigation is stressed.5. Discrepancies between the effects of the ‘height of cutting’ treatments in this experiment and those reported by other workers are indicated, and it is shown that these discrepancies probably result from the varying cutting frequencies adopted.6. Cutting the sward at varying stages of growth and increasing the rate of fertilizer nitrogen application had very similar effects on mixed herbage and clover yields in this experiment to those reported previously by other workers.7. Where the total amount of fertilizer nitrogen applied over the season was small (4 cwt. ‘Nitro-Chalk’/acre) delaying the first dressing until after the first or second cut reduced the dry-matter and crude-protein yields of mixed herbage, and had little effect on those of clover. A similar delay where greater total amounts of fertilizer nitrogen were used (8–12 cwt. ‘Nitro-Chalk’/acre) reduced the dry-matter yields of mixed herbage, and slightly increased the dry-matter and crude-protein yields of clover. Under these heavy nitrogen treatments the crude-protein yields of mixed herbage decreased only where the delay involved a reduction in the total amount of fertilizer nitrogen applied over the season.8. Although delaying the first dressing of the season reduced mixed herbage yields at all fertilizer nitrogen levels, it resulted in a more uniform distribution of production over the season. The practical significance of this is discussed.

Description: Thirty-six Hereford dwarfs, ‘comprest’, dwarf-like, and eight controls were available. Body and skin measurements were taken and the types of head abnormalities and cardiovascular activities were recorded. Haematological tests and chemical analysis of blood and hair were carried out.Typical dwarfs showed characteristic head abnormalities with varying degrees either at birth or later in life, possibly as a result of different stages of development at which the defective gene(s) comes into operation. There were progressive changes (qualitative and quantitative) in the expression of dwarf characteristics. Typical dwarfs were chronic bloaters, with pot-shaped belly or with normal belly. Atypical dwarfs were either stunted, showing (miscellaneous) deleterious genes or ‘comprest’ types. The daily live-weight gain of typical dwarfs ranged from 0·71 to 1·69 with an average of 1·26 lb. (controls 1·72 lb.). Body, head, and limb indices in typical dwarfs are similar to those of the ‘comprest’ and the control animals at comparable weights. Volume index was higher in the control than in the typical dwarfs. In the bloater dwarfs the width of the body at the shoulder region was considerably narrower. Skins of the typical dwarfs were thinner. The bloater dwarfs showed a diurnal bloat cycle (in relation to feeding time) as judged by body circumference. The severity of bloat was irregular.There was no significant difference between typical dwarfs and control animals in rectal temperature, pulse rate, blood, specific gravity, prothrombin time, sedimentation rate, red cell count, electrophoretic pattern of serum proteins, serum creatine and creatinine and calcium/phosphorus ratio in hair samples. Typical dwarfs had slower respiration rate, lower blood haemoglobin, haematocrit, and white blood count than did the controls. Post-mortem examination of dwarfs did not show similar causes of death in each case. The heart of the dwarfs was spheroid, showing severe dilation in most cases.

Description: Two procedures were followed to train boars to mount a dummy sow for semen collections. Of thirty-nine boars which were introduced to the dummy sow with no previous training twelve were trained successfully. Of eight boars which were first allowed daily mating with an oestrous sow in the pen housing the dummy sow, seven were trained successfully.Measurements of semen characteristics were made on twenty-five fertile boars including nine boars (morphological characteristics only) in use at commercial insemination centres.The mean ejaculate volume of thirty-four ‘first’ ejaculates was 173·7 ml. (range 85–275 ml.). The mean volume of the fluid fraction was 109·3 ml. (range 15·220 ml.). For second ejaculates these values were 156·9 ml. (range 80·220 ml.) and 93·2 ml. (range 25·165 ml.).The mean sperm concentration in thirty-five ‘first’ ejaculates was 284·5 x 106/ml. (range 11 × 106/ml. to 925 × 106/ml.). The mean concentration for ten second ejaculates was 224·4 × 106/ml. (range 18 × 106 to 295 × 106/ml.).In samples collected in successive 20 ml. fractions the highest concentration was found in the first 20–40 ml. In some boars the spermatozoa were distributed more uniformly throughout the ejaculate than in others.The mean number of spermatozoa per first ejaculate was 28·26 × 109 (range 0·77 × 109 to 80·0 × 109). The mean for second ejaculates was 15·88 × 109 (range 0·76 × 109 to 44·17 × 109). The mean initial pH of thirty-four first ejaculates was 7·22 (range 6·85–7·9); for second ejaculates it was 7·54 (range 7·22–8·0).There was a marked increase of pH with time after collection when semen was stored in open vessels; this did not occur when semen was stored in filled stoppered vessels.The mean pH of the sperm fraction in six ejaculates was 7·06 (range 6·8–7·4); the mean pH for post-sperm fractions of the same ejaculates was 7·36 (range 7·0–7·6).The freezing points of three ejaculates were –0·54, –0·55 and –0·56° C.The mean methylene blue reduction time for seven ejaculates was 5·0 min. (range 2·5–6·5 min.). The reducing power of boar semen was virtually unaffected when all the spermatozoa were killed by freezing.Motility of boar semen was lost rapidly when it was examined under a cover-glass; motility was restored by aeration (removal and replacement of the cover-glass).The mean percentages of nine morphological classes of spermatozoa in ejaculated semen of fertile boars were as follows: Malformed heads, 3·0; malformed middle-pieces, 2·7; bent tails, 4·5; coiled tails, 0·9; headless, 0·3; tailless, 0·3; broken necks, 0·1; neck beads, 11·8; middle-piece beads, 17·18.The decline in the concentration of spermatozoa in successive fractions of an ejaculate was associated with a decline in the frequency of middle-piece beads.The semen of one sterile boar showed a mean frquency of 77% malformed middle-pieces.The mean percentages of the above classes in samples from the vasa deferentia of nineteen fertile boars were: malformed heads, 5·7; malformed middle-pieces, 5·1; bent tails, 3·6; coiled tails, 0·06; headless, 0·6; tailless, 0·3; broken necks, 0·1; neck beads, 17·4; middle-piece beads, 59·2.The average percentages in samples from vasa deferentia of four sterile boars were: malformed heads, 11·9; malformed middle-pieces, 30·7; bent tails, 9·1; coiled tails, 0·5; headless, 0·4; tailless, 0·5; fractured necks, 0·9; neck beads, 24·2; middlepiece beads, 30·0.The mean testis and epididymis weights were 359·2 and 84·7 g. Expressed as percentages of body weight the weights were 0·285 and 0·068. The mean within pair differences in weights were 48·9 g. (between testes) and 8·5 g. (between epididymides).The macroscopic and microscopic histological features of the testes are described. Tubular atrophy associated with impaction was found to be a common feature of this sample of boar testes. There was no clear relationship of the histological features of the testes either to semen characteristics or to fertility. It is shown that fertile boars may show grossly pathological testes characteristics. The cause of the observed pathological changes was not identified. The findings are discussed.