1917] ANIMAL PRODUCTION. 869 



birds, together with unpublished data on the transplantation of the ovary into 

 castrated males, tend to show that different parts of the soma react in different 

 ways to the secretion of the gonads. Each character appears to be more or less 

 independent of every other character, just as they are in heredity. The charac- 

 ters affected are (1) those including some of the secondary sexual characters 

 that are independent of either ovary or testis, such as size in the female, voice 

 and some phases of behavior, and mandible color in ducks; (2) those affected 

 by the testis, such as comb and wattles, fat deposition, size in the male, and 

 some instincts and summer plumage in ducks; and (3) those that are affected 

 by the ovary, such as plumage form and color and some phases of behavior. 



" If the entire series of altered individuals is examined, it is apparent that 

 it may be looked upon as a series of sex intergrades. That is, characters that 

 are normally found iu one sex may be experimentally transferred to the opposite 

 sex while individuals composed of mixtures of such characters may be ob- 

 tained." 



Determinate and indeterminate laying cycles in birds, L. J. Cole {Ab$. in 

 Anat. Rcc, 11 (1917), No. 6, pp. 504, 505). — The author has noted two distinct 

 types of laying cycles in birds, one in which the number of eggs which will be 

 laid in the clutch is definitely determined when laying begins, and the other in 

 which the number of eggs that will be laid depends upon stimuli received after 

 laying has begun. In other words, the stimulus for cessation of laying and 

 inception of brooding has already been received and the reaction predeter- 

 mined in the first case, while in the second the stimulus is received later and 

 is followed by cessation of liberation of ova fi'om the ovary, though laying con- 

 tinues for a time afterwards until the ova already discharged have received 

 albumin and shells and have been expelled. The most important stimulus for 

 the onset of broodiness and the consequent cessation of laying in the second 

 class of cases is probably a physiological reaction of the female to a number 

 of eggs in the nest. As a consequence, if the eggs are removed as laid the 

 stimulus does not occur and laying continues beyond the regular clutch to an 

 indefinite number. 



Among domesticated birds the pigeon may be taken as an example of the 

 determinate type and the common fowl of the indeterminate. Among wild 

 birds experiments have been carried on with the English sparrow and the house 

 wren, which also appear to represent the two types respectively. 



A study of broodiness in the Rhode Island Red breed of domestic fowl, 

 H. D. GooDALE {Abs. in Anat. Rec, 11 (1911), No. 6, pp. 5S3, 534).— In addition 

 to results already noted (E. S. R., 36, p. 173), the author points out that the 

 length of the period before the first broody period appears in Rhode Island 

 Red hens may vary from a month up to two or even more years, while a very 

 small percentage have never exhibited signs of broodiness. Ninety-five per 

 cent, however, of the birds go broody before July 1 of their pullet year. The 

 number of broody periods depends in part on the date of the first broody period 

 and in part on the time the bird stops laying in the fall, and may vary from one 

 to eleven times during the first year. In the second year broody periods begin 

 as soon as the bird lays a comparatively few eggs. 



Breeding for egg production. — II, Seasonal distribution of egg production, 

 E. D. Ball and B. Aldek (Utah Sta. Bui. 149 (1917). pp. S-71, figs. 29).— In 

 continuation of previous data (E. S. R., 37, p. 369), this is a discussion of the 

 seasonal distribution of egg production during the first, second, third, and 

 later years of egg laying of the same flocks of hens, and a comparison of the 

 distribution of production of high-laying and low-laying flocks in the same sea- 

 son and different seasons, as well as of high-laying and low-laying individuals 

 32950°— 18— No. 9 6 



