COLORATION IN POLISTES. 67 



closeness of relation between the two is confirmed further by Frederick 

 Smith. In the Trans. Ent. Soc. for 1873 Smith states that P. chiiiensis, 

 of Hakodadi, Hiogo, Shanghai, Hongkong, and Siberia, is not in his 

 opinion specifically distinct from P. diadcma, Europe. This species, 

 furthermore, is related to P. hebrcaus, of China and Japan. He states 

 that the Japanese and Chinese form of the latter species differ greatly 

 in coloration from any seen in India ; but the palest colored examples 

 of the species from Japan very closely resemble the darkest ones from 

 India. Smith's description of these species is very inadequate, but 

 inspection of the figures given by De Saussure (24) shows that the 

 coloration of species for this region is very similar to if not identical 

 with that of the pallipes and carolinus types of the United States. 



We thus arrive at the following conclusions : Comparing America 

 with the continent of Eurasia, we find in both, distributed throughout 

 their western parts, a similar form, whose coloration is in the main 

 black and yellow. In America it is called P. aurirer ; in Europe, P. 

 gallicus. Throughout the eastern parts of the two continents we 

 find another series of very similar forms, whose coloration is mainly 

 red-brown, varied with black and yellow. In America this is repre- 

 sented by the pallipcs and carolinus types ; in Asia by P. chinensis and 

 P. hebrcBus and their varieties. Along both eastern and western coasts 

 of these continents the forms show marked increase in melanism as we 

 proceed northward, and both types come together in the interior of the 

 two continents by means of numerous transition forms. (See PI. VI.) 



I do not know that this relationship between the two continents 

 has been made out with any degree of detail for any other group of 

 animals, but as long ago as 1859 Asa Gray (9) pointed out the general 

 accord between the flora of Japan and eastern America. In a lecture 

 delivered before the students of Harvard University in 1878 he expressed 

 the relationship as follows : 



Let me recall to mind the list- of kinds of trees which enrich the Atlantic coast 

 but are wanting at that of the Pacific. Now almost all of these recur in more or 

 less similar but not identical species in Japan, North China, etc. Some of them are 

 likewise European, but more are not so. Extending the comparison to shrubs and 

 herbs, it more and more appears that the forms and types which we count as pe- 

 culiar to our Atlantic region, when we compare them as we first naturally do with 

 Europe and with our West, have their close counterparts in Japafl and North China. 



Distribution in South America. 



De Saussure (24) has described and figured a large number of 

 species of Polistes for South America, but his specification as to 

 locality is oftentimes so loose that I rely mainly on the collection from 

 Brazil made by Mr. H. H. Smith, to which I had access through the 



