[Keprinted from SCIENCE, N. S., Vol. XXV., No. 

 646, Pages 792-794, May 17, 1907 ; and No. 647, Pages 

 828-83%, May 24, 1907} 



THOSE of you who were present at the last 

 annual meeting of the Botanical Society, at 

 New Orleans, will remember that I presented 

 a paper upon the latent characters of a white 

 bean, showing that the appearance of two new 

 characters in the F 1 hybrid offspring of a 

 white bean when crossed with a plain brown 

 or yellow bean, demonstrated the presence of 

 a color-pattern, and of a pigment-changer as 

 ' latent ' characters in the white bean, latency 

 meaning simply invisibility and not dormancy. 

 On this basis it was predicted that in the 

 second generation five forms would appear ac- 

 cording to the well-known tripolyhybrid ratio, 

 27 :9 :9 :3 :16. These forms in the order of the 

 ratio are purple mottled, black (dark purple), 

 brown mottled, brown, and white. I show you 

 to-day samples of these five predicted types 

 taken from the second generation. 



The ratios of these several groups have not 

 yet been determined because not all of the 

 material has been worked over, but the pres- 

 ence of the predicted types especially the 

 presence of the two forms, plain black and 

 brown mottled, which were not known to have 

 ever occurred in the ancestry on either side 

 sufficiently demonstrates the correctness of my 

 interpretation of the allelomorphic composi- 

 tion of the parents. Some additional unex- 

 pected types were found which must await 

 further breeding experiments before their sig- 

 nificance can be profitably discussed. 



1 Read before the Botanical Society of America, 

 at New York, December 29, 1906. 



