Glover & Robinson (1953) showed that for practical purposes the rainfall at a station in any month of the year can be assumed to be normally distributed, and that the probability of the rainfall being above a certain minimum value (selected with regard to crop requirements) can be calculated accordingly. If the rainfall in any one month is distributed independently of the rainfall in other months of the year, or season, then the probability of a pattern of rainfall month by month can be calculated by multiplying the several probabilities of the individual months. It was suggested that, in general, this was sufficient; but a method was given for obtaining the probability of a given pattern when association existed between the different months. In this the correlated monthly rainfalls, xi, were transformed to uncorrelated variables Yi. The value of each Yi, when all xi take their minimum values, was calculated and called ‘minimum Y’. The probability that each Y would exceed this ‘minimum Y’ was calculated and the probabilities multiplied.

1. Observations, mainly concerning the fleece and pigmentation, were made on about 80 F1 Merino × Herdwick sheep. Of these, nine were used for intensive fleece studies, and skin samples were obtained from six.

2. Pigmentation in all the F1 lambs was greatly reduced as compared with the Herdwick breed, the majority being entirely white on the main fleece area, with varying amounts of black and brown speckling on the face, legs and neck. A few were entirely white, like the Merino. The shade of colour of the Herdwick dam did not affect the amount of pigment on her half-Merino offspring.

3. The fibre type array most frequently encountered was one not previously described, which has been named Incline. Fine Plateau arrays were also frequent, especially on the mid-side and britch positions. Other arrays which occurred were Coarse Plain, Fine Plain, Ravine, and Coarse Plateau.

4. The hogg fleece weights averaged approximately 4·5 lb. for females and 5 lb. for males, which is about double the average weight of Herdwick hogg fleeces. In general appearance they showed some superficial resemblance to Romney and Corriedale fleeces, but there was much variation between individuals. None closely resembled either parental fleece type, but the Merino influence was much more manifest than the Herdwick. Kemp, if present, was usually long and fine, resembling hair.

5. Growth of the experimental animals was normal. In an endeavour to assess conformation, measurements were taken on a few sheep, and compared with similar measurements on Herdwick and Swaledale.

6. The follicle population showed characteristics of both parental breeds, and varied greatly between individuals. The highest S/P ratio was 9·0, with a follicle density of 3000 per sq.cm. In comparison with the British breeds previously studied, autumn and winter fibre shedding was delayed and reduced in the crossbreds.

7. Thetotal number offibresper tattooed square remained stable after sample 2 (about 2 months old). There was no significant difference between sheep or between samples in percentage of coarse, medium and fine fibres, but there was a highly significant difference between positions S (shoulder), A (last rib), B (britch) and D (rump). Mean fibre density was approximately 3000 per sq.cm., and mean fibre quality proportions (by number) in the A position was coarse 10%, medium 24% and fine 66%.

8. Nearly 85% of the total clean weight of wool produced was grown in the late spring and summer months. The total wool grown was divided into three qualities and the proportion of the total weight derived from each quality was coarse 23·69%, medium 41·21%, and fine 35·10%. The distinction between the three qualities was often quite doubtful and never as clear as in the Herdwick breed. There were significant differences in proportions of coarse, medium and fine wool, between regions, between seasons and between sheep.

9. In the discussion, which concludes the series of studies of fleece and follicle population, the following topics are treated: error of estimate of proportions in work of this kind; time of development of post-natal secondary follicle, and theories of the possible influence of primary follicles on the development of secondary follicles; post-natal growth in size of follicles in Merino and other breeds; autumn moult; recapitulation in follicles during regrowth after fibre shedding; significance of fibre type arrays; origin of the Longwool breeds; protective birth-coats; pigmentation; ‘lift’ in British wools; and the possibilities of establishing a breed with the Merino type of fleece on British hill and mountain farming areas.

Lodging and yield of winter wheat were studied in a factorial experiment on land infested with the fungus Cercosporella herpotrichoides Fron. causing Eyespot. Two varieties, Squareheads Master 13/4 with long, and Bersée with short, straw, were compared at two seed rates; sulphate of ammonia was applied at 0, 2, and 4 cwt./acre at four different dates; four of the 8 blocks of 10 plots were sprayed in March with sulphuric acid to control eyespot.

Lowering the seed rate from 3 to 1½ bushels/acre decreased eyespot and the area lodged and increased the mean yield of the 2 varieties by 4·9 cwt. in unsprayed and 2·1 cwt./acre in sprayed plots. Spraying the variety Squareheads Master decreased the straws with severe lesions from 66 to 17%, decreased the area lodged from 95 to 36%, and increased grain from 22·4 to 32·4 cwt./acre; spraying Bersée decreased severe lesions from 56 to 15%, decreased lodging from 54 to 1% and increased yield from 32·6 to 43·5 cwt./acre.

The mean percentage infection at harvest was little affected by nitrogen applied in March, April or May, but was decreased by nitrogen applied in October. In contrast, the time of applying nitrogen greatly affected the weight of straw and the extent of lodging, both of which were increased more by top dressings in March and April than by those in May. Plots that received nitrogen in March and October had similar weights of straw, but the latter, with less eyespot, lodged less. Where lodging was slight, grain yields were increased equally by nitrogen applied at each date; where lodging was extensive, yields were depressed by dressings in March and April, and increased by those in October and May. Sulphate of ammonia, applied at 0, 2 and 4 cwt./acre to sprayed (upright) plots of Bersée, yielded respectively 36·8, 42·9 and 47·3 cwt. of grain, whereas applied to unsprayed (completely lodged) plots of Squareheads Master yielded only 22·4, 22·0 and 22·9 cwt./acre respectively.

1. A short description is given of an apparatus that aims at measuring the motility of sperm cells in an objective way.

2. In this method it is necessary to know the concentration on the slide for the determination of the value that indicates the motility. It was intended to measure this concentration with the same apparatus.

3. The measurement of the concentration met with some difficulties. A large scatter in the results was observed. This scattering is partly apparent in that it is caused by real differences in the concentrations which originate in the preparation of the slides. However, this apparent scatter hinders the determination of the exactness of the measurements. An estimate has been obtained, among other things, by means of a photographic experiment. There is some justification for expecting that a sufficient exactness can be obtained.

4. Notwithstanding the unexplained, and for the present still undoubtedly too large a scatter in the concentration measurements, a series of measurements of motility were made. The motility appears to be measurable by the apparatus, but there is still too great an error, so that the measurement does not yet come up to the visual method.

5. An effort to measure motility independent of the concentration on the slide (determination of the speed histogram) did not succeed because facilities were not available.

1. The digestibility of the carbohydrates in compounded poultry diets has been estimated, using both conventional and individual methods for certain components.

2. In the conventional analysis, crude fibre was apparently digested to the extent of 5%; this has been shown to be due to the comparison of different complexes in the food and the droppings.

3. Sugar and starch were digested by birds of all ages, and cellulose and lignin were indigestible. The digestibility of pentosan increased with increased age of the bird.

4. By deleting crude fibre and adopting available carbohydrate for the partition of the carbohydrate complex in foods, the nutritive ratio of a compound diet can be estimated from analytical data, and the amount of extra protein necessary when a diet is supplemented by fat can be calculated.

1. Three groups of mature ewes were fed during pregnancy and lactation on rations differing in their calcium content. The mean daily intakes of calcium were 1·4 g. (group A), 4·5 g. (group B), and 7·4 g. (group C). Blood samples were analysed monthly for calcium and inorganic phosphorus. The ewes were killed at approximately 100 days after parturition and the skeletons isolated. Individual bones, either whole or divided into definite fractions, were analysed.

2. The level of calcium intake was without effect on the number of lambs born, birth weight, or growth while milk fed.

3. Blood calcium was significantly lower in group A than in groups B and C, but blood inorganic phosphorus was unaltered.

4. The resorption of bone substance was greater in group A than in groups B and C.

5. The severity of resorption varied between bones, and in regions within certain bones. Resorption was most severe in the vertebrae and pelvis, and only slight in the metacarpal, the metatarsal and the shafts of other long bones. Resorption of intermediate magnitude was found for the remainder of the skeleton.

6. Resorption was accompanied by reductions in the percentages of ash in bones, but this effect was proportionately less than the ash weight reduction.

7. Radiological observations made on flesh-free bones at the end of the experiment gave a picture of resorption similar to that presented by the data for ash weights and percentages of ash, namely that resorption was much greater in group A than in groups B and C.

An experiment, carried out to determine the effect of dressings of sulphate of ammonia on an established lucerne-cocksfoot ley grown in narrow rows on heavy gault clay soil, is described and the results discussed. The experiment was carried out over 3 full years (1948–50) and the first crop of the following year. The results suggest that it is possible to increase the yields of grass and total produce without decreasing the yield of lucerne but that no marked increase in the yield of nitrogen per acre is to be expected. Of the times of application tested February proved the most effective.

Nitrogen, at the rate of 0.5 cwt./acre, was applied to winter wheat as an April dressing of nitrochalk, or as eight sprayings of 2% NH4NO3 solution applied either to the soil or to the leaves at about the period of maximum leaf area, before and during ear emergence. All three methods of nitrogen application caused similar increases in yield and nitrogen content of grain. April nitrogen gave a greater yield of straw than the later dressings.

Late nitrogen application caused a small increase in leaf area index, first noticeable one week after ear emergence and persisting for another four weeks. L.A.I. of plots that received nitrogen in April was much larger than that of the other plots at the period of maximum leaf area, but by four weeks after ear emergence it was less than that of plots receiving the late nitrogen. Shoot number per metre and leaf area per shoot were increased by early nitrogen, but only the latter was increased by nitrogen applied at ear emergence.

Leaf area duration after ear emergence was the same on all nitrogen-treated plots and the yield of grain divided by L.A.D. was nearly constant for all plots.

Applying nitrogen late, after an April dressing, did not prevent the rapid fall in L.A.I. from the high value reached at the period of maximum leaf area and caused no greater increase in yield than when applied in the absence of an April top-dressing. A single urea spray applied in early June increased yield to the same extent as the ammonium nitrate sprays.