POLYMORPHISM. 



97 



14. The phthisogyne arises from a female larva under the same 

 conditions as the phthisaner, and differs from the typical female in the 

 same characters, namely absence of wings, stenonoty, microcephaly and 

 microphthalmy. It is unable to attain to the imaginal instar. 



15. The worker (ergates) is characterized by the complete absence 

 of wings and a very small (stenonotal) 



thorax, much simplified in the struc- 

 ture of its sclerites (Fig. 8, C, etc.). 

 The eyes are small and the ocelli are 

 usually absent or, when present, ex- 

 tremely small. The gaster is small, 

 owing to the undeveloped condition of 

 the ovaries. A receptaculum seminis 

 is usually lacking, and the number of 

 the ovarian tubules is greatly dimin- 

 ished. The antennas, legs and man- 

 dibles are well developed. 



1 6. The gyncecoid is an egg-laying 

 worker. It is a physiological rather 

 than a morphological phase, since it is 

 probable that all the worker ants when 

 abundantly fed become able to lay 

 eggs. Wasmann (19040) observed in 

 colonies of Formica rnfibarbis that one 



FIG. 58. Pseudogyne of Myr- 

 inica snlcinodoides, with vestige of 

 fore wing on left side. (Original.) 



or a few workers became gynsecoid 



and functioned as substitution queens. In colonies of the Ponerine 

 genus Lcptoycnys ( including .the subgenus Lobopclta (Fig. 137), and 

 probably also in Diacaiinna and Champsomyrmex), the queen phase 

 has disappeared and has been replaced by the gynsecoid worker. 



17. The dichthadiigyne , or dichthadiiform female is peculiar to the 

 ants of the subfamily Dorylime and probably represent a further devel- 

 opment of the gynaecoid. It is wingless and stenonotal, destitute of 

 eyes or ocelli, or with these organs very feebly developed, and with a 

 huge elongated gaster and extraordinary, voluminous ovaries (Figs. 

 141, A, and 147, b and r). 



1 8. The macrergate is an unusually large worker form which in 

 some species is produced only in populous or affluent colonies (For- 

 mica, La sins ). 



19. The micrergate, or dwarf worker, is a worker of unusually 

 small stature. It appears as a normal or constant form in the first 

 brood of all colonies that are founded by isolated females. 



20. The diucryate, or soldier (Figs. 52, A ; 60, a ), is characterized b}' 



