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Scientific Proceedings (132) 



birds were healthy when killed for examination at 7 to 12 months 

 old, and only healthy birds are usable in the comparisons made 

 in this table. The tabulation indicates that the size of the 

 suprarenals of the grafted birds (10.2 mgms. for females; 9.8 

 for males) was not measurably different from that of the con- 

 trol (10.3 for females; 10.6 for males). The body weight of 

 the transplanted birds was somewhat smaller, for both males 

 and females, than was that of the control. The significance of 

 this difference is questionable; the data can be of value only in 

 connection with further results obtained on other animals. 



The data obtained for the age of maturity and for gonad size 

 in the birds receiving the transplants are of greater interest on 

 account of their bearing on the view of Varaldo, 1 Krabbe, 2 and 

 others, concerning an antagonism between the suparenal cortex 

 and the sexual glands of the female. The few data of table I 

 indicate that the ovaries of the transplanted birds were smaller 

 than the ovaries of the control (169 mgms. and 237 mgms.), 

 while the testes of transplanted birds seem larger than those of 

 the control (1070 and 706 mgms.). It must be said, however, 

 that the variability is great, that the individual differences show 

 no relation to the number of grafts made, and that our data 

 standing alone are quite inadequate. In fact our complete data 

 indicate that the transplanted males probably did not develop 

 functional sperm as early as the transplanted females produced 

 eggs — nearly all of the earliest eggs produced being infertile, 

 though the operated males and females were kept constantly 

 together. Even this latter observation is further complicated by 

 the fact that this group of females showed a strong tendency to 

 mate with females, and with the further fact that their eggs were 

 produced at a very early age. 



The early maturity of the transplanted females is perhaps the 

 point of greatest interest in the data of table I. These birds 

 produced their first eggs at an average age of less than 157 days. 

 Less than 157 because one of four birds (Nos. 1, 3, 6 or 7) pro- 

 duced a single egg at an earlier age than that given in the table. 

 The mothers of these birds produced their first eggs at an aver- 

 age of 204 days; but this comparison with their daughters is 

 not entirely fair since these mothers were not killed at early 



1 Varaldo, F. R., Zentralb Gynakol., 1913, xxxvii, 13.10. 



2 Krabbe, K. H., New York Med. Jour., 1921, cxiv, 4. 



