( .M> BRITISH OKTHOPTEIIA. 



and /1'injfli much as in the male ; abdomen broader. 

 Elytra in the form of short lobes, but possessing 

 veins. l\'i/ir/s rudimentary. Supra-anal plate deeply 

 notched. Oatheca with dorsal suture. Third segment 



o 



of (inlrmidB longer than the second. 



OOTHKCA (fig. 13, nos. 2 and 3).- -In B. orientalis 

 the dark brown swollen ootlieca, with dorsal suture, 

 measures about 12 mm. by 6 mm., and contains two 

 rows of eight eggs each, carefully fitted to economise 

 space. It is carried for a time (as to how long 

 opinions differ) protruding in an upward curve from 

 the extremity of the abdomen. One observer gives 

 12 hours only as the period during which it is 

 carried ; but probabty the usual period is a longer one 

 than this. The time which elapses before hatching 

 occurs is apparently a variable one also. It has been 

 recorded that this period extends to twelve months; 

 but Brindley, in the course of experiments made in 

 1897, found that "all cases that hatched did so 

 within a few days after deposition." Although it 

 might at first appear so, this subject is not easy of 

 investigation. 



^ .- 



NYMPH. It is very difficult, as Brindley found, to 

 rear cockroaches from the egg in captivity, and it 

 would seem that only a small percentage of eggs hatch 

 from the oothecaa, that are placed in a position selected 

 by the parent insect. According to Westwood the 

 embryos, when ready to emerge, eject a kind of saliva 

 from their mouth, with which to soften the ootheca 

 along its serrated edge, and so make emergence easy. 

 On escaping the nymphs are Avhite and wingless ; 

 otherwise they are miniatures of their parents. It is 

 not quite certain whether or not a moult immediately 

 occurs ; one takes place about a month later, and 

 another at the end of the first year. Further moults 

 occur at the end of each year, till, after six or seven, 

 the nymph becomes an image. Growth, therefore, is 

 slow. Wing-rudiments are present during the last 

 two or three stadia. When the time for the final 



