At the beginning of the present century Heape (1900), describing the sexual season of mammals, pointed out that sheep in the British Isles are sexually active during only a portion of the year.

A study has been made of the distribution of the various fractions of phosphorus in the Blairmont clay soils. Nearly three-fifths of the total phosphorus is present in the organic and inorganic alkali-soluble forms.

The organic alkali-soluble phosphorus and the exchangeable phosphorus vary in direct relation to cane production and to phosphorus content of the juice. The Truog phosphorus values are nil for all three soils and do not give a satisfactory indication of the phosphorus-supplying ability of the soils.

The soils have a high anion exchange capacity (23· mmol. of phosphorus per 100 g. of soil). It is indicated that the high fixing power of these soils for phosphorus is largely a mechanism of anion exchange reactions.

Two examples are given of field trials for which randomized blocks would seem the most suitable design, but in which special considerations of the future of the trial or the nature of the treatments make complete randomization impossible or impracticable. A type of design which takes account of these difficulties is described, together with the appropriate methods of analysis.

The author wishes to thank Mr S. C. Pearce for much valuable advice throughout this investigation.

Using microbiological methods, thiamin, riboflavin and niacin have been determined in individual milk samples taken from a number of ewes at intervals during their lactation. Although considerable individual variations were found, the average values of 0.67μg./ml. for thiamin, 5.68μg./ml. for riboflavin and 4.80μg./ml. for niacin in New Zealand ewes' milk are somewhat higher than those reported by overseas workers. No lactational effects are apparent from the results presented.

Milk production is of fundamental and practical importance in all farm mammals. With dairy cattle in particular extensive study of milk secretion has resulted in raising the milking performance in all domestic breeds. This has mainly been achieved by the adoption of improved breeding and feeding practices.

A study of the published data for feeding-stuff composition, digestibility and starch equivalent has shown that a linear relationship exists between the crude-fibre content and digestibility, and between crude-fibre content and starch equivalent.

No significant difference was found between the regression coefficients for crude fibre and digestibility for sheep and cattle, but the coefficients for horses and pigs were notably larger, and significantly so for pigs.

For pasture herbage the relationship between protein and starch equivalent was found to be merely a reflexion of the fibre content, and the regression coefficient between them became non-significant when crude fibre was included in the regression analysis. An equation has been obtained connecting crude fibre with starch equivalent, which is valid over a wide range of pasture species and fibre contents.

1. A series of experiments was carried out to assess the importance of the sense of smell to the grazing sheep.

2. The results of the first two experiments described indicated that the sense of smell is of importance in the initial stimulation of appetite, but under the experimental conditions the selection of particular herbage species was not affected.

3. Further experimentation showed that, because of its adaptation character, olfaction can only be of supplementary importance in influencing the food selection of the grazing sheep.

A new, rapid method for the determination of cellulose has been investigated, and has been shown to yield a fraction composed mainly of hexosan. The method has been shown to be applicable to feeding-stuffs and faecal material, with a satisfactory degree of accuracy.

1. Sweet corn is adjusted to the conditions of North America. British climatic conditions differ from American in the longer summer day-length and in lower spring soil temperature. Cold hardiness, i.e. the ability of the seed to germinate after lying in cold, wet soil, is therefore an important factor when introducing sweet corn into Britain.

2. Varieties germinate differently according to when they are sown. Furthermore some varieties germinate better than others in March and even April, thus demonstrating the genetic nature of cold hardiness.

3. Selections were first made from plants surviving March sowings and in later years, as hardiness increased, from those surviving February sowings.

4. Selections for hardiness were made in (i) Canada Gold, (ii) Early Golden Market sweet corn, (iii) Golden Standard Maize dent corn and (iv) derivatives of Peruvian crossed sweet corn.

5. All responded rapidly in their increased ability to germinate from February sowings except the Peruvian sweet derivatives which failed to show much improvement.

6. Future breeding work in Britain depends on establishing from our selections cold hardy inbreds able to combine well in giving good F1's for commercial use.

Sampling methods for the estimation of annual production and mean egg weight have been examined, and an attempt made, by a combination of theoretical considerations and practical observations, to derive general expressions for the standard error of such estimates. Numerical values of these errors have been tabulated in a form suitable for direct application by the practical poultry worker.

The author wishes gratefully to acknowledge the assistance and criticism given him by Dr F. Yates, and by Mr F. J. Dudley of the National Institute of Poultry Husbandry.

Since sheep failed to associate either a red or blue colour with the palatability of their food during the course of an experiment designed to test for colour vision, it was concluded that sheep are colour blind.

Three methods for the determination of cellulose have been compared for their value in nutritional studies, and have indicated the applicability of the procedure of Druce &Willcox (1949) in this connexion.

The use of the method of Crampton & Maynard (1938) has been shown to give an erroneous picture of the extent of cellulose digestibility, and it has been concluded that the procedure is not satisfactory.

The mean fibre length, mean fibre diameter, mean fibre crimp ratio (i.e. ratio of length of the fibre under 2·5 mg. load to its length stretched), and a quantity approximately proportional to the ultimate tensile fibre strength, have been measured for twenty-five skirted Merino fleeces clipped from sheep that had been grazed at Robe (South Australia) on copperdeficient land and fed by mouth with amounts of copper varying from zero to 100 mg./day. Sulphur analyses and qualitative amino-acid analyses were carried out on some of the fleeces. The fleeces were processed one by one on the worsted system into yarn. The results show an increase in fibre diameter, an increase in ultimate tensile strength and an improvement in behaviour in processing with increasing dietary supplement of copper.

A contribution to these experiments through special skill or knowledge has been made by almost everyone on the staff at Torridon, and especially by the late W. L. Semple, J. G. Martindale and H. Beevers. Thanks are due to Messrs Isaac Holden and Sons Ltd. for their generous co-operation in carrying out part of the work at their mill and to Mr A. Prescott, Mr F. Sharp and Mr G. W. Owen of the Wool Control, and Mr F. R. Emmett of Messrs Laycock, Son and Co. Ltd., for their assistance in judging tops. The author would like to thank Mr B. H. Wilsdon, the Director of Research, for suggestions and encouragement during this work, and the Council of the Wool Industries Research Association for permission to publish this paper.

1. Data are presented on the volume and other dimensional relations of structures in the skin of four sheep of the Romney Marsh breed, namely a lamb aged 1 month, a ram aged 2½ years and two 8-year-old ewes. All the animals were in good condition when the skin samples were obtained, yet the skin of both ewes contained structures believed to be degenerating follicles.

2. A method was developed by which it was possible to measure the volume of follicles and other structures in the skin, with an error of less than 1%. This method involved the tracing of projected images of horizontal sections of a selected follicle bundle throughout its depth in the skin, and measurement, by means of a planimeter, of the areas of structures shown on each tracing. The volume was calculated from the sum ofall the areas multiplied by the thickness of the sections. A method was also evolved of measuring the curled length, as distinct from the ‘depth’, of a follicle. The difference between the length and depth of the majority of the follicles in these samples was less than 10%.

1. Records of mortality of Dairy Shorthorn heifer calves in the N.I.R.D. herd from 1924 to 1946 were analysed and show a total loss of 16·3%. Losses due to abortions amounted to 5·1%, to stillbirths 6·3%, and post-natal losses in calves up to 6 months of age, 4·8%.

2. The mean adjusted length of gestation period for 230 Dairy Shorthorn cows was 285·6 days.

3. Calves carried longer were heavier at birth, the average increase in weight amounting to 0·91 lb. per day of gestation.

4. The adjusted mean birth weight of the calves was 81·68 lb. Bull calves are carried longer than heifer calves by about 1·68 days and they are heavier at birth by about 3·29 lb.

5. The birth weight of 111 heifer calves born between 1940 and 1947 was 79·9 lb. as compared with the value obtained before the war of 87·0 lb. for 285 heifer calves.

Some factors affecting the weight of the calf at birth were studied; including the effect of artificial mating.

The development of the follicle population in lambs of the English Leicester and Romney breeds has been studied in relation to the developing fleece, skin and fibre samples being taken at four ages, namely at 1, 3, 6 and 9 months after birth. The technique used in obtaining skin samples and preparing them for examination, and of obtaining estimates of the follicle population, and the data thus obtained, are presented and discussed in the foregoing pages. Although as a result of technical difficulties and other misfortunes the complete set (1943). The follicle group in the samples taken at 1 month old showed primary follicles on the ental side, large secondary follicles along the ectal margin, and smaller secondaries, or secondary follicle primordia, situated towards the centre of the group. Accessory structures (sweat gland, arrector muscles) usually associated with primary follicles only, may occasionally be found in connexion with follicles situated on the ectal side of the follicle bundle, and apparently corresponding to large secondary follicles. Attention is drawn to the fact that a group of secondary follicles normally develops around the ectal aspect of each primary follicle, whether the latter is solitary or one of a couplet or trio. It is suggested that the ‘primary group’ (one primary and its associated secondaries) is a fundamental unit of the fleece, although generally included within the trio group.

1. Methods for the determination of lignin which involve the use of 72% sulphuric acid have been reviewed.

2. Three methods in common use, viz. those of Norman & Jenkins (modified Common), Crampton & Maynard (modified Lancaster) and of Ellis, Matrone & Maynard were studied, and comparisons made of their relative effectiveness.

3. That of Crampton & Maynard was considered less satisfactory than the modified Norman & Jenkins procedure, on the grounds that it contains several sources of error, the most serious of which are the use of formaldehyde and the failure to remove pentosans.

4. The yields of lignin obtained with the method of Ellis, Matrone & Maynard are appreciably higher than those resulting from the modified method of Norman & Jenkins, by reason of the failure to use a protein correction factor. When such a correction is made, results from the two methods are comparable.

A study of extracting reagents has been made to find mild but reasonably efficient methods of extracting organic matter from soil. Sodium pyrophosphate proved to be the most satisfactory of the neutral reagents tested, and the optimum conditions for extraction of organic matter from soil by this reagent have been defined.

1. The presence and distribution of divalent and trivalent manganese in pyrophosphate extracts of mineral and highly organic soils were studied.

An analysis of the breeding of 130 kinky-tailed pigs of Large White and Wessex origin indicates that the character is genetic in nature and is of variable penetrance and expressivity. The hypothesis is put forward that pigs, in general, may be charcterized by a slight tendency to this defect which is exhibited when the appropriate accidents of development occur. In addition, there may be genes which raise the overall frequency and severity of the defect. In the Large White inbred strain studied, it is thought that there were minor genes with a recessive effect as well as a major gene with incomplete dominance. In the inbred strain several litters were obtained which included no normal pigs although both parents were apparently normal. In outcrosses, kinky tails appeared less frequently. Inbred, kinky-tailed pigs were difficult to rear and of those kept for breeding most proved sterile. Post-mortem examination of a number of affected pigs showed a high incidence of abnormalities of the kidneys, ureters and genitalia. The suggestion is made that kinky tails are but a minor manifestation of an early developmental disorder.