464 POULTRY CULTURE 



such differences are individual, irrespective of sex.^ This becomes 

 apparent whenever a sufficient number of cases is considered. 

 How the hne is drawn between asexual and sexual reproduction 

 is not known. From the fact that in asexual reproduction the 

 germ carries the possibility of development of every parental 

 character, the logical inference is that a germ from any individual 

 will always carry possibilities of development of every character 

 of that individual. Wide observations of the phenomena of breed- 

 ing as exhibited in any race indicate that this inference is cor- 

 rect. Many poultry breeders will declare that the female has most 

 influence on shape and size, the male on color and superficial char- 

 acters. Observation supports the assertion that the female influ- 

 ences size (and shape, which is largely dependent on development) 

 more than the male, but this influence is exerted after transmission 

 through the special relation of the female to the embryo, and the 

 opinion is based mostly on comparisons of the offspring of different 

 females by the same male. As between two females, the one well 

 developed and vigorous, the other undersized and lacking vitality, 

 the offspring by the same sire will (conditions after the embryonic 

 stage being equal) invariably show marked difference in development, 

 due first to difference in transmission, but also to difference in nour- 

 ishment during the embryonic stage. When characters not so mate- 

 rially affected by the vitality of the dam are compared, none can be 

 found on which sex has any special influence in transmission. 



Prepotency. Observation of the common phenomena of breed- 

 ing shows that individuals vary in capacity to transmit characters. 

 Ordinarily, the average of the progeny, even of parents carefully 

 selected for quality according to the standard used, is distinctly 

 lower than the average of the parents, — though in the work of a 

 skillful breeder the average quality of the progeny in each genera- 

 tion tends steadily higher than the average quality of the preceding 

 generation as a whole. But there are frequently found individuals 

 with unusual capacity for impressing upon their progeny high quality 



1 This observation, of course, does not directly apply to what is called sex- 

 limited inheritance, where the sexes differ regularly as to the form in which 

 they inherit a particular character or characters. Yet in the last analysis it 

 does apply to such cases, as is seen when a male inherits the male form of a 

 character from the maternal line, or the female the female form of a character 

 from the male line of ancestry. 



