144 Farm Poultry 



improvements and in the development of many 

 new breeds, the male leads. As a rule, the males 

 of a breed or variety differ more from one another 

 than the females differ from each other. The 

 young more nearly resemble the female than they 

 do the male. It is also observed that the organs 

 most highly developed in the male differ more 

 than do the organs which are most highly devel- 

 oped in the female, that is, the comb, wattles, 

 and tail, which are most highly developed in 

 the male, differ more than those parts which are 

 most highly developed in the female. The im- 

 provement of domesticated fowls depends upon 

 the transmission of desired characteristics which 

 have been produced through the action of this law 

 or fact of variation. 



In-and-in-breeding. This term is often used 

 in a rather loose sense to indicate the breeding 

 together of animals which aje more or less closely 

 related. It is generally used, however, to indi- 

 cate the breeding together of animals that are 

 closely related for several successive generations ; 

 and in this sense it is used in this discussion. As 

 breeders have not agreed on an exact definition of 

 in -and -in -breeding, there is a considerable differ- 

 ence of opinion as to just what the term implies. 

 Some breeders hold that the term implies only the 

 mating of animals of the closest relationship, 

 while others strenuously maintain that more dis- 



