blattid^. 
59 
the end of the following April. The young which emerge from the egg- 
capsule are in general form similar to the adult, the skin softer, the 
antennae and cerci with fewer joints, the wings absent. The number of 
moults is not known ; in captivity, development is slow, the common 
household species (Periplaneta americana ), requiring several months to 
come to maturity. There is reason to believe this is the case also with 
the free-living species, and since the possession of wings is usually a 
matter of slight importance and the habits remain unchanged, there 
would not appear to be any necessity for quick iiymphal development. 
The total length of the life history is not known, but the imaginal, like 
the nymphal, life is probably comparatively long. 
In all stages, cockroaches are found amongst fallen leaves, on the 
surface of the soil, under stones, in thick grass, and on trees and plants. 
The majority are nocturnal, living in concealment on the surface of the 
soil and forming a part of the large ‘‘surface fauna.” The tree and 
bush species are diurnal in habit. A few are household insects living in 
buildings and these are undoubtedly wild free-living species which have 
migrated into man’s dwellings. The food consists of dead animal and 
vegetable matter; these insects are “scavengers” and none is known 
to feed on living plant tissue or to attack living insects. Plant sap, de¬ 
caying plant tissue, dead insects and the like probably represents the 
food of the free-living species. The household species have the same 
food-habits, a great variety of animal and vegetable substances forming 
their food while their dead brethren are freely eaten when hunger 
presses. Nothing is known as to the activities of Indian species during 
the different seasons. Hibernation, where necessary, is apparently pass¬ 
ed in any stage and there appear to be no special ‘ ‘seasons’ ’ when 
cockroaches breed. Excessive cold, excessive heat, drought or hunger 
cause a cessation of reproduction, development and activity but no 
definite seasons have been made out. No species is known as a pest, 
though those which live in houses are objectionable and destructive. 
Since these insects are dependent upon crumbs, scraps, and access to 
human food, cleanliness and care should prevent them thriving. Where 
they are abundant, the simplest precaution is the use of borax, mixed 
with double its weight of syrup, as a poison ; many ingenious traps are 
also useful when baited with intoxicating liquor. The principal check 
