THE PROBLEMS IN MATING AND IN EGG PRODUCTION 127 



Chance Fertilization. — It is much the same as in a game of 

 chance. If there were ten sets of the table of sixteen placed 

 in a lucky bag we should not expect the one (WWRR) and 

 the one (bbss) to be drawn with each sixteen, although we 

 know that there would be ten of each drawn by the time the 

 one hundred and sixty tickets had been drawn. 



This is the common experience of breeders. It sometimes 

 happens that the best birds of the year's breeding come all at 

 once, at some period of the season, while at other times they 

 are fairly evenly distributed all through. 



It is like the game of whist. Each player knows that there 

 are four aces in the pa,ck, and that four out of fifty two cards 

 are of this nature and are dealt every time. The average is 

 absolute, but the individual chance of getting one ace each 

 hand is uncertain. 



In an experiment there were bred a number of Rose-comb 

 Buff Orpingtons. Both parents had rose combs, but there 

 was produced a fair proportion of single comb chickens. 

 These were the recessives, bred because one of the parents 

 was a D.R. and not a pure dominant. The single-comb reces- 

 sives were not bred together, but there were mated two single- 

 combed pullets bred in this way to a pure single-combed Buff 

 Orpington cock. In this case there was a pure single comb 

 and a recessive single comb, which should have bred pure 

 single combs, but the result was a third of apparently pure 

 rose combs, and some of the single-combed chicks has side 

 spikes, as if a trace of the rose-combed blood showed itself 

 in the hinder part of the single comb. 



These rose-combed chicks continued to be bred from the 

 single-combed progeny for two generations. This shows the 

 dominance of the rose comb, but it also shows that the domi- 

 nance may lie dormant in a recessive character, and when 

 fresh blood is introduced may take the opportunity of a new 

 combination to reassert itself. 



The recessive character may therefore be incomplete as well 

 as the dominant; but the occurrence is so rare that the excep- 

 tion may be taken as proving the rule. 



