PRACTICAL VALUE, OF THE. MENDEL LAW. 23 



To illustrate by an example : 



Suppose a breeder of fowls of a five toed variety secures two males of that variety having 

 only four toes ou each foot, and with these males as a starting point proposes to change his 

 stock from five toed to four toed. 



Now if Mendel's law is a law of prepotency he might get opposite results from the matings 

 of these two males with one hen each. He might have the progeny of male No. 1 all four toed 

 like the male, and the progeny of male No. 2 all five toed like the female. If then on inbreed- 

 ing individuals from each mating he found the variations as to toes approximately according to 

 Mendel's results, this would be the situation : From the progeny of male No. 1 he would have 

 seventy-five per cent of four toed chicks, and only twenty-five per cent of five toed chicks. 

 From the progeny of male No. 2 he would have seventy-five per cent of five toed chicks, and 

 only twenty-five per cent of four toed chicks, but, the four toed chicks from male No. 2 

 would be the ones of most service to him, because he would know that they would reproduce 

 themselves with certainty, while only an unknown in every three of the four toed chicks of the 

 progeny of male No. 1 would be pure bred as to the number of toes required. 



Thus it will be seen that if it could be established that the Mendel law applied to some things 

 in poultry breeding, a breeder acquainted with this law who should produce from a mating, or 

 discover that a chance mating had produced a lot of chicks divided with respect to any par- 

 ticular character, as the offspring of Mendel's crosses were divided, might reasonably assume 

 that he had found an in?-tance where the law applied, and proceed to make his matings 

 accordingly. 



We can see, too, how the discovery that this principle applied In any particular case might be 

 of great importance in the preservation of established characters. One of the greatest difficul- 

 ties in breeding poultry is fo hold points gained while making changes in other points. The 

 knowledge that certain individuals, or the entire progeny of a certain mating, or line of mak- 

 ings, was especially strong in capacity to withstand change as to any particular point, would 

 be extremely serviceable. 



Then, too, as has probably already occurred to many readers, where Mendel's law applied a 

 breeder might find his best course in working for some special point, to breed first for its con- 

 trary or opposite; in other words, to try to make it a " recessive " character, and so determine 

 the individuals possessing it in purity perhaps several seasons earlier than would otherwise be 

 possible. 



It is too soon to say yet just where and how Mendel's law applies, but it is certain that it 

 'does apply in some cases, and altogether probable that investigation will show It of great use to 

 poultry breeders. To make it useful to themselves poultrymen must familiarize themselves 

 somewhat with it and with investigations along the same lines, and must also do what they can 

 in the way of making observations to discover whether or not it applies with respect to any 

 particular phenomena of breeding. 



