THE COCKROACH : 



of the Cockroach. The first change of skin occurs immediately 

 after escape from the egg-capsule, the second four weeks later, 

 the third at the end of the first year, and each succeeding moult 

 after a year's interval. At the sixth moult the insect becomes 

 a pupa,* and at the seventh (being now four years old) it 

 assumes the form of the perfect Insect. The changes of skin 



Fig. 6. Young nymph (mule). X 0. 



are annual, and like fertilisation and oviposition, take place in 

 the summer months only. He tells us further that the ova 

 require about a year for their development. These statements 

 are partly based upon observation of captive Cockroaches, and 

 are the only ones accessible ; but they require confirmation by 

 independent observers, especially as they altogether differ from 

 Hummers account of the life-history of Blatta germanica, and 

 are at variance with the popular belief that new generations of 

 the Cockroach are produced with great rapidity. 



The antennae of the male nymph resemble those of the adult 

 female. Wings and wing-covers appear first in the later larval 



* The use of the term pupa to denote the last stage before the complete assump- 

 tion of wings in the Cockroach, is liable to mislead. There is no resting-stage at all ; 

 wings are developed gradually, and are nearly as conspicuous in the last larval state 

 as in the so-called pupa. There seems no reason for speaking of pupre in this case. 



It is preferable to designate as "nymphs" young and active Insects, immature 

 sexually, but with mouth-parts like those of the adult. See Lubbock, Linn. Trans., 

 1863, and Eaton, Linn. Trans., 1883. 



