COCKROACHES, ETC. 143 



containing twenty or more eggs ; these cham- 

 bers along the front of the egg-case are quite close 

 to the exterior, and the young larvae, when ready to 

 emerge, have only to force their way through the 

 opposed walls of the membranous partitions to gain 

 the outside world. The spongy outer covering is 

 fabricated by the mother, and serves as a protection 

 against the attacks of ants and other enemies of that 

 sort. I once found resting on the egg-case of a 

 Mantis a species of Braconid, a Hymenopterous 

 parasite with a very long ovipositor, and it is possible 

 that this insect was meditating an attack on the eggs 

 of the Mantis. Its ovipositor was certainly strong 

 enough to penetrate the outer spongy coat of the egg- 

 case and long enough to reach the egg-mass inside. 

 But my approach scared the creature away, and I 

 successfully reared a numerous progeny of Mantids 

 from that egg-case. 



The newly hatched larvae swarm out of their egg- 

 case in scores all at the same time, and look rather 

 like long-legged ants, and if not supplied with suitable 

 food in the form of mosquitoes or other minute flies, 

 they will commence to devour each other. Brongniart, 

 who has studied the emergence of the larvae of some 

 Algerian Mantidce, states that the newly hatched young 

 do not leave the egg-case at once, but for several days 

 remain hanging from it by means of two slender 

 filaments emerging from a pair of jointed appendages, 

 the cerci, at the end of the body. Then the larvae 

 cast their skins, which are still left hanging to the 

 egg-case, and drop to the ground. I have observed 

 the emergence of the young of many species, but have 

 never seen this appearance ; the young have always 



