THK ORGANS OP NUTRITION. 119 



94. 



We shall show in full detail, at its proper place, that the character 

 of the organs of the animal sphere differs wholly from the vesicular 

 character of the vegetative organs by the integral solidity of each indi- 

 vidual part. 



FIRST CHAPTER. 



OF THE ORGANS OF NUTRITION. 



1. THE INTESTINAL CANAL AND ITS APPENDAGES. 



95. 



The intestinal canal (tractus intestinorum) is the internal tube, 

 extending from the MOUTH, appropriated to the reception and trans- 

 formation of the nutriment. It has in general a second aperture opposed 

 to the first, the ANUS, through which the indigestible unassiuiilating 

 remains of the food are rejected. The instances in which such an anal 

 aperture is deficient are very rare among insects, and occur only among 

 larvae and maggots, but never in the imago. 



This tubular structure of the intestinal canal is subject to con- 

 siderable modification from distension and constriction, by means of 

 which it is separated into several divisions, which have very justly 

 received different names, from their functions being dissimilar. Be- 

 sides these separations of the intestinal canal itself, we observe 

 peculiar processes and appendages, which originate from it, or 

 which, as perfectly independent parts, merely open into it. Their 

 variety and modifications produce relations which yield multifarious 

 differences in form and structure, and which link certain groups of 

 insects more closely together by their complete uniformity, whereas 

 they separate others, in which such a similarity of arrangement is not 

 observed, more distinctly from each other, and thus more fully corro- 

 borate the dissimilitude expressed in their exterior conformation by this 

 difference of their internal structure. 



