716 THE AMERICAN NATURALIST [Vol. XLIV 



If we consider both parents of the fourteen albinos 

 listed in Table a as simplex in pigment, i. e., as having 

 not only normal but also albinic germ-cells, they were 

 "DR's." When two such simplex (DR) individuals are 

 mated, we expect 25 per cent, of the offspring to be 

 duplex (DD), 50 per cent, simplex (DR or RD), and 25 

 per cent, without pigment (RE). Only the last will be 

 albinic, 75 per cent, will be of normal color. We actually 

 find that with fourteen albinos there are associated in 

 their fraternities 37 + or 38 + normal individuals, ex- 

 pectation being 42. The deficiency would doubtless be 

 accounted for by the unincluded normal children. Since 

 the proportion of albinic offspring in the given fraterni- 

 ties accords with expectation on the assumption that 

 albinism is recessive that assumption is justified. 



Second, if albinism is recessive, it should not appear 

 in offspring of albinos with normal consorts. Unfortu- 

 nately the sterility of the cross makes it difficult to get 

 the desired data, but so far as they go, they are not in 

 disaccord with hypothesis. 



III. One Pakent Albinic 



