INDIVIDUALS AND SPECIES 41 



Not only do the individuals of a given genera- 

 tion receive an extensive assortment of character 

 combinations, but also, because of their distribu- 

 tion over a considerable area, they are certain to 

 encounter different environmental conditions. The 

 species embraces all of the variety of individuals 

 resulting from the combination of these diverse 

 fundamentals. It is a product of heritage and en- 

 vironment, but in such a degree of diversity as 

 cannot be exemplified by a single individual or 

 even by a group of moderate size. 



In a given location at different seasons the en- 

 vironment may vary so much that individuals of 

 the same species may resemble each other no more 

 than individuals of closely related species. These 

 differences may be associated with conditions of 

 light, moisture, or temperature. Henneguy, in 

 speaking of this phenomenon, mentions Pieris 

 octavia-seramus, a butterfly of the Transvaal, as 

 one striking case. Of its wet and dry season forms 

 he says: "La forme seramus, de la saison humide, 

 presente une paire d'ailes anterieures dont la face 

 superieure est coloree en rouge, souvent avec bor- 

 dures et taches noires, et dont la face inferieure est 

 presque aussi vivement coloree. La forme octavia, 

 de la saison seche, a les ailes d'un bleu vif tache de 

 rouge en dessus et d'un noir verdatre en dessous." ^^ 



This type of variation is of relatively little im- 



** Les insectes, p. 516, 1904. 



