1880.] NATURAL SCIENCES OF PHILADELPHIA. 383 



lies, and the vanit}' of military glory ! This incident, and many 

 other observations, go to establish that in the function of the 

 warrior is the true economy of this ant. The manner in which 

 her European congener Rufescens makes her raids upon the nests 

 of Formica fuse a and F. cunicularia, marching in solid column, 

 and conducting war with activity, intelligence and success, may 

 be read in the fascinating pages of Huber and Forel. There is no 

 doubt that our American species has precisely the same habit. 

 Mr. Joseph Jeanes, a well-known member of this Academy, has 

 described to me the raids of an ant observed by him upon his 

 conntrj'-place at Fox Chase, which, from his description of the 

 insect, without a specimen, I should have little hesitation in identi- 

 fying as our P. lucidua. 



The slaves, however, are not deficient in the combative faculty 

 They spring to repel a hostile attack as freely and fiercely as the 

 masters. They do this independent!}-, too, just as they conduct 

 their mining operations, and their abilit}'^ to wage successful war- 

 fare seems to be quite in keeping with their mai'tial spirit. Dr. 

 Darwin has conjectured,^ that the slave-making instinct may have 

 originated from the unintentional rearing of pupfe collected for 

 food, who proving themselves useful and congenial inmates of the 

 nest, suggested the collecting of pupjae to be reared. Thus origin- 

 ated a habit, which by natural selection was strengthened and 

 made permanent, and finally increased and modified, until an ant 

 was formed as abjectly dependent on its slaves as P. rufescens. 

 Whatever credit we may give to this ingenious hypothesis, it 

 must be said, that in the case of our F. ScJwjiJf'ussi, natural selec- 

 tion has not operated to degenerate the soldierly courage and 

 faculty, and remand the duty of defense to those associates in 

 whom the military faculty has been specialized. In other words, 

 if Lucidus has become specialized as a warrior, dropping an origi- 

 nal disposition and ability to labor, her slave has not become 

 specialized as a worker, nor dropped her combative faculty, but 

 seems to be possessed in all respects of the normal habits and 

 nature of ants of her species. At least I could trace in her no 

 effects of slavery, other than the strange association with and care 

 of her abductor. One, therefore, who accepts Dr. Darwin's sug- 

 gestion, must allow that natural selection has wrought toward 

 specialization in one section of the colony, but has been suspended 



' Origin of Species, p. 26. 



