STRUCTURE AND DEVELOPMENT OF EMBIA TEX ANA. I I/ 



occur in late June, at the very height of the dry season. But as 

 these frail insects cannot undergo heat and drought, as has 

 already been shown, it seems not improbable that soon after the 

 last stage described above there is an arrest in development which 

 enables the embryo to aestivate within the protecting chorion until 

 the rains of later summer. Under the conditions of Texas 

 weather it does not seem likely that there are two broods a year. 

 Moreover, from autumn till spring there is a gradual increase in 

 the size of the larvae observed. 



The few stages obtained show nothing but what might be ex- 

 pected in the development of this insect, and simply indicate that 

 the position of the Embiidae in the superorder Orthoptera is 

 doubtless correct. The latter part of the embryonic history, at 

 least, shows a closer parallelism with the Termitidae than Grassi's 

 conclusions drawn from the adult structure would lead us to ex- 

 pect. At any rate, the comparatively large size of the head of 

 the young embryo, the persistence of the abdominal legs and the 

 structure of the appendages and of the "tail-piece" might have 

 some phylogenetic bearing. The late formation of the eyes, the 

 enlarged front metatarsi, the relative sizes of the antennas and 

 maxillary palpi are marks of specialization, indicating arrested or 

 precocious development, and are not to be sought for beyond the 

 ontogeny of this form. 



SUMMARY. 



The females of the Embiidas are comparatively large, wing- 

 less and symmetrically formed, the males have the abdomen 

 more or less distorted (except species 17, 18 and 22). The 

 males of probably all the species are dimorphic, being wingless 

 (not dealated) or winged. The wings arise from invaginations at 

 a pre-nymphal instar. A nympha-stage with larva-like body 

 is undergone. Venation varies with the species, and generally is- 

 double, represented by true veins and pigment lines. The thick- 

 ened veins of texana are few. Copulation occurs within the nests. 

 The carriage of the male abdomen is attributable to its function. 

 The facets of the Embiid eye are quite like those of a newly- 

 hatched grasshopper. 



The entire family is tropicopolitan and prefers the humidity of 



