OP INSECTS. 
143 
parts more distinctly defined, and so much elongated,, 
that the whole digestive tube exceeds from six to 
twelve times the length of the body. The changes 
which it undergoes in the progressive developments 
of a Lepidopteron, ( Pontia Bra$sicce, the common 
cabbage-butterfly,) as traced by M. Herold,* are 
principally the following : In the Caterpillar there 
is a very short esophagus, with salivary vessels ap- 
pended to it; an extremely large cylindrical stomach, 
and a short intestine, succeeded by a wide but short 
csecum. Shortly after the chrysalis is formed, the 
esophagus is found to have become longer and more 
slender; the stomach to have decreased greatly, 
both in length and diameter, while the intestine is 
elongated, and the ccecum terminates in a pretty 
distinct rectum. As the chrysalis becomes older 
farther changes ensue, and about eight days from 
the time of its assuming that form, the sucking- 
stomach can be discerned, and the stomach begins to 
separate into two portions. These changes are more 
sensible when the butterfly is on the point of being 
disclosed, and after that event the esophagus is 
very long and slender ; the sucking-stomach in the 
shape of a large vesicle ; the stomach double ; and 
the intestine very long and convoluted. Analogous 
changes take place in many other tribes, into the 
consideration of which we cannot now enter. 
To what has been said respecting the anatomical 
features of the great alimentary organ, it may be ad- 
* “Entwickelung-Geschichte tier Schmetterlinge, &c. 1 vok 
4to. Cassel und Marburg, 1815. 
