



%. 





?f*SF-iBF^ 



»*'^" V ' '* 



-^ 



•»-«,-- -^- 







PLATE V. The effect of genetic factors on the pigmentation of newts, 

 (a) larvae of Triturus rivularis; (b) larvae of T. torosus; (c) hybrids of 

 T. rivularis X T. torosus. (d) transplantation of pigment cell primordium 

 from T. torosus into T. rivularis; (e) ditto from T. rivularis into T. torosus. 

 The pigmentation in the area occupied by the graft is the same as that in 

 the species to which the graft belongs. After Twitty. 



