No. 591] NOTES AND LITERATURE 



191 



appear, in Africa. Punnett suggests that the details in pattern 

 may be in slight measure affected by the plant species on which 

 the caterpillars have fed, thereby producing local races. Trans- 

 portation of a local race to a region inhabited by another dis- 

 tinct local race "would help us in deciding whether any varia- 

 tion by which it is characterized had a definite hereditary basis 

 or was merely a fluctuation dependent upon something in the 

 conditions under which it had grown up." We may well ask: 

 are these two propositions mutually exclusive? May not a de- 

 tail of color pattern to a certain degree at certain times be sub- 

 ject to environmental influences and at the same time may not 

 its variations have a "definite hereditary basis?" The re- 

 viewer has had so much experience in observing the transmis- 

 sion in Colias philodice and C. eurytheme of spots comparable 

 to that mentioned in D. chrysippus that he is convinced that a 

 definite hereditary basis (consisting presumably of multiple 

 factors) underlies every fluctuating detail of color pattern. By 

 artificial selection from inbred stock, using uniform food plants, 

 and exposing the caterpillars and pupae to similar conditions, 

 the breeder of butterflies may decrease even to elimination or 

 increase within certain limits a detail of color pattern like that 

 mentioned. The champions of the theory of mimicry are en- 

 titled to this crumb of comfort. "For if it can be supposed," 

 remarks the author, "that small differences of this nature are 

 always transmitted, it becomes less difficult to imagine that a 

 mimetic resemblance has been brought about by a long series of 

 very small steps." 



Yet the facts which the mimicry theory seeks to explain clamor 

 for explanation. Punnett sets forth at the end some that are 

 most insistent. 



Certain color schemes are characteristic of distinct geographical re- 

 gions in South America, where they may occur in species belonging to 

 very different genera and families. 



In Central America a pattern occurs that is common to sev- 

 eral Heliconines, Ithomiines, Nymphalines of two or more gen- 

 era, and Pierids; in eastern Brazil another pattern in which 

 "all the various genera which figure in the last group are again 

 represented. ' ' On the upper Amazon a still different pattern is 

 common to the same group of genera from that just mentioned, 

 only two notable genera being absent. Finally in Ecuador, Peru 

 and Bolivia a widely different pattern occurs in a group lacking 



