432 WILLIAM M. MANN 



dered. Regarded in this way, the familiar statement that para- 

 sites cannot become lobbers loses its significance as an argument 

 against the derivation of sanguined from rufa-like ancestors, for 

 sanguined comes not from rufa, but from a rw/a-like type, with 

 a loss of colony-foundation instincts, which does not involve 

 parasitism. Neither does this mean degeneration, but rather a 

 high development, as in the present day rufd. Viehmeyer's 

 opinion that these species are doomed to extinction seems 

 "curious" to Bum, considering the immense, size of the colo- 

 nies of rufa; as "curious" as the organic and psychical degenera- 

 tion which he thinks he finds in the high psycho-plastic endow- 

 ment of sanguined. In saving the psycho-phylogeny of his 

 robber stages, Viehmeyer assumes that the females of sanguined 

 originally took part in the robber raids of their colonies, but 

 this opinion is too uncertain to be taken seriously in the dis- 

 cussion. Brun concedes Wasmann's derivation of dulosis in 

 Formica from a facultative adaption stage to be the weakest 

 part of his theory. The apparent analogy of permanent dulosis 

 and temporary parasitic colony foundation will not stand strong 

 criticism, because we do not know that the colonies are exclu- 

 sively founded with the aid of fusca. We can account for the 

 social parasitic condition of rufa only by assuming a condition 

 involving the loss of the ability to establish a colony unaided, 

 and this loss could have been due as directly to the pupal- 

 robbing habit as to obligatory social parasitism. Wasmann did 

 not mean that a subparasitic condition was a step toward dulo- 

 sis, any more than he wished to deduce the already developed 

 social parasitism from dulosis. He considers dulosis in sanguinea 

 a direct engraphic influence. Through the presence of fusca in 

 the nest the young sanguineas are influenced to raise the fusca 

 pupae obtained by raids, and care only for those whose smell is 

 similar to their own. This psychological reason of Wasmann 

 does not seem to Brun to hold, for the tendency of sanguinea 

 is not limited to fusca pupae, but extends also to allied species. 

 This, Brun explains, is a fixed, inherited association from anal- 

 ogy. The workers in colonies not socially parasitic often show 

 just as strong a tendency toward dulosis. 



Brun is not inclined towards Wasmann's hypothesis of the 

 origin of dulosis in Formica from facultative social parasitism, 



