management we are unable to say. Its occurrence in the three latest consecutive years favors the latter explanation. There is at any rate no such general increase in August production as was noted in the Wyandottes. Since an increase in August production would be most probably due to a general recovery of the flock from broodiness, it would seem just to conclude that broodiness persists longer in Rhode Island Reds than in Wyandottes. The groups differing in fecundity differ but little in the proportion of egg production occurring during the summer months (Table 11c). The distribution of egg production during this period is somewhat different in the three groups (Table 11b). In the low group production falls most rapidly from June to September, in the medium group there is a steady but less marked decline, while in the high group there is a fall in production from June to July, a recovery in August, and sustained production through September. In the high group June production resembles spring rather than summer fecundity. These fowls laid as many eggs in June as they did in April. The summer season in this high fecundity group is a period of sustained rather than declining egg production. The August recovery is probably due to the greater number of broody birds returning to production in this than in the lower groups. The month of September should properly be included in the summer period for this breed. It partakes of the characteristics of summer rather than autumn production in all years and all groups. AUTUMN The autumn period of production in this breed should consist, our data show, of only one month, October, although it obviously extends into the following one or two months not covered by our data. It is marked by a distinct decline in egg production in all years and by a sharp rise in the proportion of fowls not laying (from 10 per cent in September to 31 per cent in October). Both of these changes are related to the beginning of the fall molt and reproductive rest on the part of many of the fowls. The effect of this physiological change is most evident in the low fecundity group and is less marked in the medium and high groups. A greater proportion of annual production occurs in October in the high than in the lower groups. For the whole group of fowls the rate of decrease of egg production in the autumn is about the same as the rate of increase during the winter, although the low level of the period of first egg production is not reached at the end of the year. From the foregoing discussion it is plain that egg production in Rhode Island Reds follows the same general seasonal cycle as that already established in Wyandottes and other breeds. Detailed comparisons are reserved for a later bulletin. The period covered by the contest statistics although arbitrary is found to correspond to a single orderly series of changes in egg production reflecting changes in the reproductive and allied. mechanisms of the fowl. These changes are in general gradual and in the group as a whole merge one into another without sharp breaks. Attainment of maturity, mating and reproduction, sustention of egg laying interrupted by broodiness, rest and moulting recite the physiological changes in the body of the fowl, and these with their concomitant changes in egg production occur in a continuous cycle. Alterations in these seasonal changes have been made by selective breeding in the past and distinct differences in the seasonal distribution of egg production are evident between fowls of high and low fecundity. The curve of seasonal egg production has been levelled out in the highest groups, the chief additions to fecundity having occurred in the winter and autumn, bringing them up more nearly to the level of the spring season; while the curve describing seasonal variation in the fowls of low fecundity retains the spring peak of the wild fowl cycle with but little anticipation of this cycle in the winter months and only a meager continuation of it into the summer. CHANGES IN THE SEASONAL DISTRIBUTION OF EGG PRODUCTION It is an interesting question whether any of the changes noted above have taken place in the fowls entered in the contest during the nine years under consideration. Has the proportion of egg production in the winter tended to increase toward the level characteristic of the highest producers, and what changes if any have taken place in the egg production of other seasons? The solution to this problem may be sought by methods similar to those used in studying the trend of mean egg production during the nine years. We have set out in Table 8 the proportion of total annual production occurring in each season of each year. The seasonal distribution is found to vary somewhat in different years. It has apparently not been seriously affected by the abnormal conditions in 1913 and 1918, although the winter production in the former year is somewhat low. Winter Total Theoretical Change Omitting 1913 & 1918 9 years Omitting 738 -2.002 |y=22.630.082x|y=23.993-.286x Summer y=28.557-.081x y=27.469+.122x| We have fitted to each series of seasonal percentages, the straight line most nearly describing the changes occurring between 1911 and 1919. The equations to these lines are given in Table 13. From these equations it may be concluded that there is no significant direction to the annual fluctuations in seasonal egg production. The tendency has been for production to be distributed through the year in about the same way in each of the nine years. There was, to be sure, a tendency toward decrease in winter production which would become somewhat more marked if the low year 1913 were omitted, but in none of the seasons is the whole change indicated in the nine years greater than one per cent, which would appear to be well within the probable error of the method. This result is in contrast with the gradual but steady increase in winter production which was noted in the Wyandottes. A comparison with other breeds will be made in the final bulletin of this series. It is interesting to examine the changes in the seasonal distribution of egg production brought about by the same conditions which caused the low average production in 1913 and 1918. In Table 8 it is found that in 1913 the flock laid a smaller proportion of its eggs in the winter and a larger proportion in the spring and summer than in any other year. In 1918 the seasonal distribution of egg production departs but little from the normal. The actual numbers of eggs produced in the seasons of these years are given in the table following for comparison with the numbers produced in the seven normal years. Winter Spring Summer Fall The amount by which egg production in 1913 deviated below the average is spread unevenly through the year being greatest in winter and spring and least in summer and fall. The conditions causing the low production of 1913 were chiefly operative in the beginning of the year. The deviations of 1918 are spread more evenly through the year, the largest decrease below normal coming in the summer. The conditions causing low production in 1918 were characteristic, therefore, of the year as a whole. The actual conditions will be considered in the final comparative bulletin of this series. CONCLUSIONS A summary of the principal results of this study will be found on the first page of the bulletin. The principal value of these results is the basis they afford for comparison with other breeds and the provision of normal data on egg production in this breed. In general it appears that this breed, if we may take the 1132 birds considered as a fair sample, has undergone some improvement in egg production in the nine years. The changes have, however, been slight, except for the evident tendency to ward increase in the most fecund classes. The seasonal distribution of egg production, which indicates the amount by which selection is changing the wild or original type of egg production has shown no tendency to change during the nine years. BIBLIOGRAPHY. DUNN, L. C. 1924-Bulletin 117, Storrs Agr❜l Exp. Station. GOODALE, H. D. 1918-Journal Agr'l Research Vol. 12: pp 547 574. HARRIS, J. A. and GOODALE, H. D. 1923-Genetics Vol. 7: pp 446-465. KIRKPATRICK, W. F. and CARD, L. E. 1917-Bulletin 89Storrs Agr❜l Exp. Station. |