mi9] m \i. pRomjonoH". - : | 



Hakkis (Quart. Pubs. Amer. stnti*. A**or., n. *cr., 15 (1911). So. 120. pp. 85+- 

 859). — Formulas are derived to facilitate the computation of ncta coefficients 

 of correlations as that between egg production of bona for ■ year and the pro- 

 duction in a particular month of thai year. 



The physiological conditioning of the secondary sexual characters in 

 birds. On the endocrine role of the genital glands, A. P| ■ \u> (Ilul. Ii«,t. 

 France et Uric;., 52 (1918), No. 1-2, pp. 176, pi. 1, figg. 79).— 1 

 ported hero, began In 1909 and brought to a sadden end by the mobilisation 

 of 1014, consist mainly of studies of the development of secondary sexual char- 

 acteristics in caponized and spayed domestic fowl and pheasants. The r.-sults 

 were similar to those of previous investigators, but an unusual effort has been 

 made to give the data quantitative treatment. In the chicken experiments Qu 

 were used 81 males and 10 females of various breeds, hut all with Single 

 combs. For each individual a table gives the body weight and the length of 

 comb, wattles, and spurs at frequent intervals for a year or more after the 

 operation, together with notes on the development of hackle, saddle feathers, 

 and sickle, the changes in color of comb and wattles, the crowing habits, and 

 the sexual instincts. The weights of the liver, the peritoneal fat, and. in Ur- 

 ease of controls, the gonads were determined by autopsy. 



The linear measurements are considered in relation to the cube root of tho 

 body weight. In the case of comb length of males castrated at an early a_ r '-, 

 this relation remained constant throughout life. In normal males, the comb 

 developed twice as rapidly as the body during the first year. Essentially the 

 same results were found with wattle length. Spurs and plumage were not in- 

 fluenced by castration. The combs of cocks castrated after puberty decreased 

 in size until a definite lower limit was reached, and the difference bet •■■■n the 

 size of comb at any period during retrogression and this lower limit was found 

 to be almost exactly proportional to the square of the time yet to elapse. In 

 the case of two cocks in which mutilated pieces of testicular tissue were In 

 sorted in the peritoneal cavity at the time of castration, the comb and other 

 erectile organs showed retrogression for about 3 weeks and then became normal 

 again. For from 4 to 8 months three capons were given frequent Injections of 

 a suspension made from the testes of a cryptorchid boar. The combs began 

 to enlarge immediately but retrogressed as soon as the injections ceased. 



Ovariotomy caused immediate growth of spurs on pullets, and after the next 

 molt the assumption of male plumage. The changes in their combs were vari- 

 able; in some cases the head resembled that of a capon. Descriptions are given 

 of a few gynandromorphs, both natural and experimentally produced. 



Confirming the observations respectively of sfaiguon (E. S. Et., 21. p. 17" » 

 and of Daniel-Brunet and Rolland (E. S. B,, 26, p. 878), the author found 

 that the percentage of glycogen in the pectoral muscles was higher in ... 

 trated than In uncastrated cocks, but that the glycogen content of the lh-r 

 of the two groups was about equal. Data are given showing the relation be- 

 tween body weight, amount of fat. and the ratio of liver weight to estimated 

 body surface in the normal and castrated males. It is concluded that the 

 capon has no abnormal tendency to store fat but has lost the power of utilising 

 it. Data on body weight, body surface, and weight of liver of growing rats 

 are presented for comparison. 



Three silver pheasants and two golden pheasants were castrated. The 

 plumage did not undergo modification bbt the sexual instincts were not de- 

 veloped. The comb- and wattle like carunculntiong characteristic of sll 

 pheasants remained small. Descriptions are given of the plumage of three wild 



