130 
ANATOMY AND PHYSIOLOGY 
being sufficiently masticated. The part last named, 
otherwise called the gullet , (PI. II. figs. 2, 3, a ,) is a 
narrow tube intermediate between the pharynx (when 
such exists,) and the crop, or, in the absence of the 
latter, the gizzard. It commonly passes through the 
thorax in a straight line, and terminates at the origin 
of the abdominal cavity; but nothing can be more 
variable than its length. In certain Hymenoptera, 
( Pimpla, Pompilus ,) it forms more than half of the 
entire canal; in the cockchafer, (PI. II. fig. 3, a,) 
a small portion behind the head, scarcely one-sixtieth 
of its length ; and all intermediate dimensions occur. 
The esophagus is in all cases simple, except among 
the Lepidoptera, which present the remarkable pecu- 
liarity of a bifurcation anteriorly, a branch emanating 
from each of the two spiral sucking tubes and uniting 
into one conduit, usually just behind the head. The 
crop, (PI. II. figs. 2, 3, b , b,) lias been so named by 
Cuvier, Leon Dufour, and Strauss, because it occupies 
the same position as the organ so called in birds ; by 
some other authors it is denominated the stomach. 
It appears, for the most part, as a simple dilatation of 
the hinder part of the esophagus into a kind of bag, 
which is usually on a line with the other parts of the 
alimentary canal, but sometimes appears suspended 
•at the aide. like a pouch. Its form is most variable, 
•even in ^he # same species, according to the degree of its 
repletion or vacuity. When the gizzard, the succeed- 
ing portion of the canal, is wanting, which is very 
’often the case, the crop appears iu its simplest form, 
and is un provided with any secretion to act upon the 
