68 Trans. Acad. Sci. of St. Louis 
time of emergence does the opening gradually form. 
One often wonders, upon picking up an empty egg case, 
how it is possible for the sixteen young to have emerged 
without leaving a break in the case. The mechanics is 
extremely interesting. As in the Carolina mantis, all the 
eggs are deposited with the head nearest the opening. 
The eggs, being produced practically at one time, or at 
least within forty-eight hours, all develop alike. In this 
mummy stage preceding emergence, the caudal end of 
the body tapers, while the greatest development is about 
the head. Now with all of the enlargement occurring at 
the fore part of the body, which is uppermost, it is easy 
to see how sixteen enlarging fore parts would mechani- 
eally and gradually open the exit, and simultaneously all 
would slide out en masse and automatically the closure 
would come together again. 
Some writers think that the young secrete a liquid 
which dissolves the cement in the seam of the capsule. 
This process is not merely an emergence, but also a 
real hatching, for in the process each insect issues from 
its individual egg shell and also from the dotheca enclos- 
ing a number of eggs. One often finds the thin, white 
caps that cover the forepart of the insect caught in the 
seam of the empty case, where the emerging nymphs have 
left them behind. In addition to this cap each mummy is 
completely enveloped in a thin, brown, papery bag, the 
egg shell. It is very pretty to see, when one splits the 
egg case in two parts, the two rows of heads facing the 
opening, wriggling and writhing out of this paper shell, 
and to see the two rows of heads, face to face, gradually 
make their appearance. I have said that at this stage the 
insect is completely white save the black eye-spots, but I 
have discovered with the aid of the microscope that the 
three teeth of each mandible are brown and seem to be 
