INHERITANCE OF PARTICULAR CHARACTERISTICS. 67 



( i ), f rotn 100 per cent to nearly zero. The second hybrids of Polish or Houdans 

 crossed with single coinbs illustrate series (2). We begin with a single comb 

 having its posterior one-sixth split ; next conies a comb having its posterior 

 one-sixth split and anterior five-sixths single, but greatly reduced in height 

 (fig. 50) ; next the same with the anterior portion reduced to an irregular 

 carunculated mass having a slight median elevation (fig. 49) , and finally a 

 pair of papillae only (fig. 48). In this series we have a fading out of the 

 median portion, part passu with the enlargement of the nostril, but the 

 persistence of the side combs unimpaired. The side combs have been unable 

 to enter the territory from which the median comb has been driven, because 

 that territory is likewise untenable for it. These two series sufficiently 

 demonstrate that the V comb represents the posterior portion of the cup comb. 



That the cup comb represents merely the greatly enlarged lateral combs 

 or side-springs is proven by the occasional presence of both median and cup 

 comb on the same individual. In some races, as in the English type of Hou- 

 dans, the median comb typically appears lying between the pair of cup-like 

 side-springs, resembling the trunk of a butterfly between its wings. Among 

 the heterozygous combs of the second generation of Minorca x Houdan or 

 Minorca x Polish hybrids, instructive examples of persistence of both single 

 comb and side-springs are especially apt to occur. Figure 52 shows this 

 condition ; there is a median comb anteriorly and a nearly typical pea comb 

 posteriorly, except that the lateral ridges are atypically high. Thus the 

 Y comb becomes explained as due to the presence of both single and lateral 

 combs. ^ 



The question now arises, Is it possible to explain on Mendelian principles 

 the production of a Y comb when median comb and lateral comb are crossed ? 

 In accordance with such principles we should have to picture the gametes 

 of the single-comb and V-comb parents as follows : 



The allelomorphs are then median and no median, no lateral and lateral, 

 and the positive characteristics are dominant. In the second hybrid gen- 

 eration the two dominant characters should be combined in nine-sixteenths 

 of all cases ; the two recessive in one-sixteenth, and one dominant with one 

 recessive in three-sixteenths + three-sixteenths of the cases. 



Another hypothesis is possible. Granting that the Y comb is no neomorph, 

 but the sum of single and lateral comb, then the Y comb may be a case of 

 particulate inheritance, the median comb being produced on the anterior and 

 the lateral on the posterior part of the frontal region. In cases of particulate 



