The Biology of the Roach 69 
thoroughly chitinized, the only heavily chitinized part 
- about the insect. 
When this mummy is removed from this bag, the head 
is inflexed, the legs, antennae and mouth-parts pressed 
flat against the body, and the segments very distinct—in 
fact, the whole organism looks like head and segments, 
and not at all like the roach it will be in five minutes. 
Even at this stage the two cerci are very prominent. 
The roach works itself out of the egg shell by a series 
of contortions, comes out through the opening and there 
sheds a white membranous cap, which, no doubt, is for 
the protection of the head. This frees its legs, and then 
the newly born roach clumsily walks away. This behavior 
is very much like that described for the praying-mantis.” 
Another irregular piece of semi-chitinous covering 
hangs from the tip of the abdomen, and this, I think, is 
the shed skin that bound the legs and antennae close to 
the body. With a few hard jerks this is left behind and 
the roach, for only now does it really appear as a roach, 
scampers briskly away. If the egg case is not artificially 
opened, it indeed seems like magic to see almost simul- 
taneously all heads protrude through the opening, 
struggle for an instant to get the limbs free, kick the hind 
legs loose from the adhering skin, and again simul- 
taneously scamper away in all directions, all in less time 
than it takes to tell. 
In opening many egg cases I found all of them fertile 
and in the same stage of development. In one case, how- 
ever, amid healthy looking organisms, were two eggs 
opposite each other, hard and brown, dead or infertile. 
Number of young in each egg case.—Notes were made 
on the number of nymphs that hatched from each of 43 
egg cases. This number varied from 12 to 18, as follows: 
*Trans. Acad. Sci. St. Louis, 22:1-57. 1913. 
