138 Annals Entomological Society of America [Vol. XIII, 



usually the third or sometimes the second moult. Primitively 

 they appear as caudo-lateral extensions of the meso- and meta- 

 nota, from which they become separated at a later stage by a 

 suture and a more constricted base. 



The leading features in the life cycles of the orders of 

 Group 1, so far as known, may be summarized as follows: 



Blattoidea. Mostly nocturnal, hiding by day, with a ten- 

 dency to be gregarious: feeding chiefly upon animal and veg- 

 etable refuse; eggs (16-50) arranged in two series in a horny 

 ootheca, formed in the uterus, and carried for a time in the 

 genital orifice; dropped in protected places without attach- 

 ment; period of growth variable, 4 or 5 months to several 

 years, but usually one brood annually; number of moults 

 variable, generally 5-7. Hibernation in egg or nymph state. 

 The adult males of some species differ considerably in form 

 from the nymphs and the adult females. Styli of female dis- 

 appearing at last moult, usually persistent in the male. 



Mantoidea. Diurnal, solitary, living on foliage or on the 

 ground, predaceous on other insects; eggs arranged in several 

 series in a membranous or vesicular ootheca formed at the 

 exit of the genital passage and attached to other objects, the 

 number deposited varying enormously in different species 

 (20-1000) ; incubation period varying according to season, a 

 few weeks (summer) to 10 months (winter) ; hatching as a 

 pronymph; number of moults 7 or 8 (Mantis); usually one 

 brood; hibernation in egg or nymphal stages. Styli as in 

 Blattoidea. 



Isoptera. Cryptozoic, living in communities, often of many 

 thousands of individuals, which are polymorphic, there being 

 in addition to the fertile adults and nymphs, sterile wingless 

 castes of one or two types (soldiers and workers) and some- 

 times reserve fertile individuals (substitution royalties), which 

 in other respects remain immature. Reproductive activity 

 limited to few individuals, the kings and queens, (and the 

 substitution royalties), the queens of enormous fecundity, and 

 having the final or reproductive stage greatly prolonged (some- 

 times several years). Superfluous winged adults leave the col- 

 ony, flying in swarms, but soon lose their wings. Food largely 

 of wood, proctodaeal excreta, saliva and organic refuse, varying 

 in composition according to caste. There are generally no 

 special modifications in the nymphs, except the lack of eyes and 



