ANIMAL PEODUCTIOl^. 573 



"From different matings where the son was bred to the mother, the pullet 

 offspring showed a lower average egg yield than others not inbred. There was 

 greater variability in production from the inbred pullets; that is. there was a 

 wider range between the highest and lowest individual records than was the 

 case with those not inbred. The vigor of the laying stock as shown by the 

 mortality records was lowest in the inbred stock. The vigor of the offspring 

 as shown by the mortality records of the chicks was lowest in the inbred stock. 

 There was a lower fertility of eggs in the inbred stock. So far as fixing the 

 character of egg production is concerned, inbreeding proved a failure." 



The author states that in all his experiments with heavy layers, with one 

 or two exceptions, a high record hen has never been secured by inbreeding or 

 line breeding. The average result from inbreeding has been lower than from 

 outbreeding. 



Additional data on effect of castration in domestic fowl, H. D. Goodale 

 (Jour. Amer. Assoc. Instr. wid In/vest. Poultry Hush., 1 {1915), No. 3, pp. 23, 

 24)- — This continues work conducted at the Oregon Experiment Station and 

 previously noted (E. S. R., 29, p. 69). 



It was found that " castration of the male brings about comparatively small 

 changes in the secondary sexual characters. A capon is externally like the 

 male, except that the comb and wattles remain small for a long time. More- 

 over, they do not as a rule crow or tread the hens. However, in some capons 

 kept for a number of years the comb and wattles began to gi'ow after 

 eighteen months of age, eventually reaching a large size. These birds crow 

 and exhibit sexual reactions. Castrated drakes, too, develop the plumage of 

 the normal male. Those castrated completely possess one peculiarity, how- 

 ever, in that they do not assume the summer plumage, but, although molting 

 frequently, always retain the so-called breeding plumage. 



" On the other hand, the female, whether duck or fowl, from which tlie 

 ovaries have been completely removed always develop male characters in large 

 measure, though the degree to which these characters develop varies somewhat. 

 In some individuals of each species the assumption of the male plumage has 

 been practically complete. The castrated pullets look very much like capons, 

 but have short legs. Sometimes, however, the comb and wattles become rela- 

 tively large. The reason for this, perhaps, is to be found in a compensatory 

 hypertrophy of the Wolfian body and duct observed in one instance, which seems 

 to persist in some normal females for some months at least. It is quite pos- 

 sible, too, that the comb and wattles of the male owe their development not 

 so much to the spermatogenetic tissue as to the epididymis. In ducks, after 

 the removal of the ovary, the plumage sometimes becomes exactly like that 

 of the male. However, in no instance has it been observed that the color of 

 the upper mandible became like that of the drake, nor has a duck been 

 observed which developed the male's voice, though in some instances they are 

 unable to produce a normal ' quack.' In some instances, too, the castrated 

 ducks develop the summer plumage. There is, however, a class of females 

 which after castration do not develop typical male plumage, but acquire a dis- 

 tinctive type, which is made up of numerous feathers of the m.ale breeding 

 plumage type and a second type bearing a close resemblance to the feathers 

 of the male's summer plumage. In some sections these last are often like those 

 of the female. These females are undoubtedly constitutionally different from 

 the others. Thus far all pure-bred females have belonged to the types jusf 

 described, while those females which develop the most perfect male plumage 

 have always been hybrids. 



" In a number of instances the complete removal of the ovary has not been 

 effected, but minute portions remained behind. In these instances the new 



