KATYDIDS AND THEIR KIN. 199 



each of these cells is a single row of cylindrical 

 pouches, somewhat similar in appearance to those of 

 a cartridge belt, and within each pouch is an egg. 

 The female cockroach often runs about for several 

 days with an egg case protruding from the abdomen, 

 but finally drops it in a suitable place, and from it the 

 young in time emerge. While this method of ovipo- 

 sition is the one practiced by all the species of com- 

 mon occurrence in the United States, there seem to 

 be exceptions to it, as Dr. C. Y. Riley a few years ago 

 recorded the fact of an introduced tropical cockroach 

 which produced the young alive. 



All young cockroaches resemble the parents in 

 form, but are wholly wingless, the wings not appear- 

 ing until after the fifth or last moult. The young are 

 often mistaken for mature individuals by persons who 

 have not made a careful study of the life history of 

 the insects; and those of one or two well known and 

 common forms have, in the past, even been described 

 or figured as distinct, wingless species by some of the 

 leading entomologists of the country. 



Although abundantly represented in individuals, 

 the number of species of cockroaches inhabiting the 

 Eastern United States is comparatively few, but about 

 twenty having been recorded. Of these, nine, repre- 

 senting five different genera, are known to occur in 

 Indiana. Of the nine, seven are indigenous or native 

 species, the other two having been introduced from 

 the Old World. 



In this connection I shall consider the habits of four 

 of these insects, the first of which is the Oriental or 

 black roach, Periplaneta orientalis (L.). This species is 



