13 



the extracted recessives which did not in sub- 

 sequent generations produce any black off- 

 spring could not do so for the simple reason 

 that the pigment-changing unit had acted in a 

 perfectly normal way and had been absolutely 

 separated out into the black offspring while 

 its recessive counterpart was segregated with 

 equal purity into the non-black. 



A very important consideration in this con- 

 nection is the frequency with which the new 

 character is atavistic. This shows the process 

 by which these various color varieties were 

 originally produced. The original character 

 was compound and the new variety was pro- 

 duced by the loss of one or more of the com- 

 ponents. In other words these varieties are 

 retrogressive. Beginning, for instance, with a 

 purple mottled bean, one variety was formed 

 by the loss of the mottling, another by the 

 loss of the pigment, and another by the loss 

 of the pigment-changer. Then by hybridiza- 

 tion every possible combination of these three 

 characters became the constant characteristics 

 of distinct strains. When these varieties are 

 crossed together the original variety may be 

 reproduced by bringing together the several 

 component parts of the original compound 

 character. 



There are still many mysteries regarding 

 latent characters or qualities, but I believe the 

 considerations here presented bring a large 

 number of otherwise anomalous phenomena 

 into perfect harmony with typical Mendelian 

 cases of alternative inheritance. It appears to 

 me certain that this conception of latent char- 

 acters as invisible ones, which has already 

 been used by Oorrens 14 to interpret in part the 

 behavior of Mirabilis hybrids, can be extended 

 to clear up his remaining difficulties, and that 

 Bateson will find in the same conception an 

 explanation of the complex behavior of his 





