248 



PRINCIPLES OF ANIMAL BIOLOGY 



Fig. 196. — Two guinea-pigs with rough coats. The hairs are in many places arranged 

 in whorls, sloping away from a central point. Rough coat is dominant over the smooth 

 coat of Figs. 190 and 191. {Courtesy of Professor W. E. Castle and the Harvard University 

 Press.) 



Fx 



jW^y'^k.ji^v''^', 



3 



Fig. 197. — Illustration of the simultaneous inheritance of two pairs of contrasted char- 

 acters. The parents are black smooth, and white rough, respectively. Black and rough 

 are dominant. The F2 generation consists of four visibly different types, in the ratio of 

 9 black rough: .3 black smooth ; 3 white rough : 1 white smooth. (From Babcock and 

 Clausen, after Baur.) 



