l6o \V. M. W11KKLKK AM) J. F. MrCLENDON. 



the dimorphism of the females of L. latipes is to be sought in -the 

 direction of hybridism or of dimorphism scnsn stricto. Only 

 further observation and especially experiment can enable us to 

 decide which of these interesting alternatives confronts us. 1 



For the present we incline to the belief that the - and /9-females 

 of latipes represent true dimorphic forms, and see in this con- 

 dition an interesting repetition of what may have led to the dif- 

 ferentiation of the primitive winged female ant into workers and 

 queens. It is granted on all sides that insects like the ants, 

 social wasps and bees, which present three sexual phases, viz., 

 males, queens and workers, are to be derived from forms with 

 only a single female form. In the bees and wasps there can be 

 no question that this original female form was winged like the 

 male, and we should expect this to be the case also with the ants, 

 but so eminent a myrmecologist as Professor Emery takes quite 

 a different view of the matter ('95/ ; , p. 775). He says : "If the 

 above considered derivation of ants from Mutillid-li'ke Hymen- 

 optera be granted, we must suppose, furthermore, that in primi- 

 tive ants, as in the Mutillicls, the males were winged, but the 

 females wingless, and that the latter subsequently reacquired 

 wings. This supposition is upheld by the fact that wingless 

 females are most commonly met with among the Dorylinae and 

 Ponerinae, /. c., in those very groups of ants which are the most 

 primitive, more rarely among the Myrmicinae, and most rarely, 

 and, so far as I am aware, only as individual anomalies, in the 

 Dolichoderinae and Camponotinae. The frequency of occurrence 

 of wingless females is, therefore, inversely as the phyletic stage 

 of development of the different groups of ants. 



1 In the Lepidoptera and Hymenoptera, if we except a few cases like the Torymid 

 Chalcididas, the female sex seems to be more prone to dimorphism than the male. In 

 Diptera the few recorded cases of dimorphism occur in males ; e. g., in the Brazilian 

 Curupira torreutiitin (Fritz Mueller, '81 ; Osten Sacken, '95) and the North Amer- 

 ican Syrphid Mallot<i cinibiciforniis (Williston, '86). Among the Coleoptera Dytis- 

 cus presents dimorphism in the females, while some of the Anthribiclse are said to 

 show it in the males. The dimorphism seen in the "high" and "low" males of 

 the Scarabseidse among the Coleoptera and the "high" and "low" male Dermap- 

 tera {Forficula auricu/aria] observed by Bateson ('94, pp. 40-42), resembles that of 

 the female L'isius latipes in being a normal and excess development of the individuals 

 of the same sex. In the latter case, however, the two forms are not connected by 

 intermediate variations. 



