THE DEGENERATE SLATE-MAKERS. 493 



nests of L. musconiin and L. tuberuin. The mixed colonies may con- 

 tain males and females as well as workers of both the host and parasitic- 

 species. The males of sublevis are so much like those of Leptothorax 

 that Adlerz failed to distinguish them till he published his final paper 

 (1896). All the females which he found were wingless and ergatoid, 

 with a thorax like that of the worker, but with ocelli and a receptaculum 

 seminis. He naturally took these ergatoids to be the only females of 

 the species, but in addition to these Viehmeyer has discovered winged 

 females in some of the colonies in Saxony. Adlerz's observations 

 seem to show that sublevis secures its auxiliaries by attacking Lepto- 

 thorax colonies, driving away the adult ants and taking possession of 

 their nests and young. The latter are then reared as auxiliaries, or 

 hosts. It is not impossible, however, that sublevis may recruit the 

 number of its auxiliaries by making occasional sorties like Polyergns, 

 for Adlerz succeeded in finding one nest in which the parasites were 

 living with two species of Leptothom.v (acervontin and inusconini). 

 The domestic instincts of sublevis are very much blunted or obsoles- 

 cent. It. rarely or never excavates, and although it is able to feed 

 itself if food is within reach, it does not go in quest of it, but leaves 

 this to its host. A number of sublevis which Adlerz isolated with a 

 number of larvae and some food managed to live for 135 days, but the 

 larvae shriveled up or died. It seems probable, therefore, that this ant 

 depends on its slaves for the nurture of its young. When the mixed 

 colony moves to a new nest the sublevis are carried by the Leptothorax ; 

 very rarely are the roles reversed. Sometimes when the sublevis 

 endeavor to leave the nest they are restrained by their slaves in much 

 the same manner as Polyergus. Adlerz observed the males mating 

 with the ergatoid females, but this occurred only between individuals 

 belonging to different colonies. The larvae of sublevis are so much 

 like those of their hosts that he could not distinguish them. They are 

 nourished both with regurgitated liquid food and with pieces of insects, 

 a method of larval feeding which was also observed by Viehmeyer. 

 This author believes that sublevis was originally lestobiotic like Sole- 

 nopsis. that is. that it once robbed and devoured the young of an ant 

 in whose neighborhood it nested without forming a mixed colony. The 

 following are his views on the phylogeny of sublevis and its method of 

 establishing colonies: " The starting point of the development was rep- 

 resented by an ant allied to Leptothorax, with males and females, both 

 winged, and, like many other ants, with a predilection for eating the 

 larvae and pupae of allied species. This habit, practiced only occa- 

 sionally at first, became established and the ants took to nesting near 

 other ants, which at first tolerated these thieves unwillingly (compound 



