143 



clothing, food stuffs, etc. The two principal household 

 species are very wide-spread in their distribution, occur- 

 ring in many parts of the world. The larger of these is 

 Periplaneta americana (Fig. 151) ; the closely related 

 form P. australasiae (Fig. 152) is slightly smaller. These 

 are the common brown cockroaches, lj inches to 2 inches 

 in length, and with a spread of wings of nearly 4 inches 



Fig. 152. Australian cockroach. 



(a) male icith icings spread ; (b) female; (c) immature form. Xatural 



size. (From U. S. Dept. Agric.) 



They are very conspicuous on moist, hot nights in the wet 

 season, when they fly into lighted rooms. The immature 

 forms are generally to be seen in numbers, if one enters 

 a kitchen or storeroom at night, carrying a light. The 

 eggs of the cockroaches are laid in masses, in the form of 

 a capsule. The young are similar in shape and appear- 



