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ANATOMY AND PHYSIOLOGY 
stages of development. The striking changes in 
outward appearance implied by the terms complete 
metamorphosis, prepare us to expect some corre- 
sponding alteration in internal organs, and this, ac- 
cordingly is found to be the case. The proportions 
of the .different parts are not only different, but 
some of the parts found in the perfect insect are 
wanting in the larva, while others exist which dis- 
appear in the final stage. Such changes are indis- 
pensable when the larva lives on one kind of food, 
and the imago on another, (as in the Lepidoptera, 
for example,) but they likewise occur in cases when 
the food is the same in both conditions. In the larva 
of the carnivorous Coleoptera, for instance, which are 
equally predaceous with the mature insect, the only 
distinguishable parts of the alimentary canal are the 
esophagus, a minute crop, a chylific ventricle, and 
a small gut — the ventricle being perfectly smooth 
externally. To what an extent this differs from the 
canal of the imago, will appear from a comparison 
with that of the common Tiger-beetle (C. campestris), 
formerly described, and figured on Plate 1st, fig. 2. 
Many instances of it being comparatively short in the 
early stages, are to be found in the same order, but 
in none is this more notable than among the phy- 
tophagous Lamellicorn beetles. That of the larva 
scarcely exceeds the length of the body, all the sub- 
ordinate parts being absorbed (so to speak) by a 
capacious stomach filling nearly the whole of the 
splachnic cavity. This expansive ventricle, after the 
last metamorphosis, becomes narrow, its component 
