430 PROCEEDINGS OF THE AMERICAN ACADEMY. 



queens. In Leptothorax tuherum, Fletcher ('89) found that workers 

 lay eggs. Workers, though very rarely, may even bear vestiges of 

 wings (Wheeler, :05®). Emery ('94, p. 54), too, states that in most 

 Ponerinae the workers are only slightly differentiated from the queens, 

 and that in several species there are intermediate forms between 

 workers and queens. Furthermore, that some species have a wingless 

 queen which is transitional between the queen and workers. Such a 

 queen is also mentioned by Wheeler (:04% p. 251). Moreover, the 

 head of the normal, winged queens of such ants as have two different 

 sorts of workers is almost always less developed than that of the 

 largest worker (Camponotus, Pheidologeton, Pheidole, etc.) ; only sel- 

 dom (certain Colobopsis and Cryptocerus) does the head of the queen 

 resemble that of the largest worker in size and form. It furthermore 

 appears (Emery, '94, p. 55) that the degree of development of the 

 sexual glands is correlated with the development of the head. 



As a rule, however, egg-laying belongs to the queen, while the 

 workers attend to the general needs of the nest, though some workers 

 do occasionally lay eggs. In a good many species they seem, according 

 to Miss Holliday (:03), to be anatomically if not physiologically adapted 

 for this. Indeed, Wheeler (:06% p. 298) says that when workers are 

 well fed, they readily become fertile, and that they can, and often do, 

 produce normal young from unfecundated eggs. But if the workers 

 may lay eggs, so, on the other hand, according to Wheeler (:03^), "the 

 females [Leptothorax Mayr] live almost like the workers, being 

 merely somewhat less inclined to work." But in some cases (e. g. in 

 Formica co7isocians, difficiUs, sanguinea, etc.) the queen has so far lost 

 her powers of performing the general work of the nest that she is de- 

 pendent on the workers of another species to bring up her first brood 

 (Wheeler, :04^ p. 359 ; :04'=; :05» ; -.05^ ; :05d, p. 399), and it is doubtful 

 whether in some species she alone could found a colony (Wheeler, :05*). 

 Again, through becoming parasites, the workers of some species in 

 several genera (Anergates, Epoecus, Tomognathus, Sympheidole, Epi- 

 pheidole) have secondarily disappeared (Forel, '95, p. 145 ; Wheeler, 

 •.04d). 



Nor are the workers of a given species themselves always alike. 

 Emery ('94), Wheeler (:07^ pp. 53-57; :08^ pp. 44-47; :10, pp. 92- 

 99), and Forel ('95, pp. 142 et seq., and :04^) describe several castes of 

 females in many species, and these authors would account for the 

 great gap between the extreme types of workers in a species by the 

 disappearance of intermediate forms (Emery, '94 ; Wheeler, :08% pp. 

 58-59; :10, p. 112; Forel, '86, p. 132; '95; :04% p. 574). On the 

 other hand, there are species in which there is still a completely graded 



