BRITISH ORTHOPTERA. 



pouch of the mother, and so the young are born alive ; 

 in other cases, even, the ootheca is replaced by a simple 

 transparent membrane also retained within the brood- 

 pouch. Some cockroaches exhibit " maternal solici- 

 tude ' by carrying their lately-hatched young.* 



When newly hatched the young are white with 

 black e} 7 es ; but they soon assume their proper colour. 

 They closely resemble the adults except for the 

 absence of wings. Post-embryonic development is 

 slight- -another sign of antiquity in the cockroach 

 group. At the fifth to the seventh ecdysis (the 

 number is uncertain) the nymph becomes an imago, 



FIG. 13. Oothecse of cockroaches. 1, of Ectobius lapponicus ( x about 

 7) ; 2 and 3, of Blatta orientalis ( x 2), 3 with one face of the ootheca 

 removed to reveal the row of eggs ; 4, of Periplaneta americana 

 ( x 2'5) ; 5, of Blattella germanica (x 2'5). 



and, in the winged species, bears the organs of flight. 

 How long an individual cockroach may live is doubt- 

 ful, but it is supposed that the term of its existence 

 may, under favourable circumstances, extend to five 

 years. 



It is interesting to note that Shelford found in 

 Sarawak some very interesting cockroaches which 

 were truly aquatic, and that Dr. N. Annandale had 

 previously found water-cockroaches in the Malay 

 Peninsula.f 



* See Shelford's 'A Naturalist in Borneo/ pp. 117, 118. 

 f ' A Naturalist in Borneo/ p. 118 et seqq. 



