ZOOLOGY. 537 



Insects ; they are, as is well known, the anterior mem- 

 bers themselves, and there is no longer therefore in the 

 Bird any feet attached to the thorax below, as in Insects. 

 Besides, if the wings did not signify arms in the Bird, 

 then it must have four legs. Thus in the Insect the 

 wings could not also mean feet. 



Their structure also speaks in favour of our view of 

 the Insect's wings. They are known to be completely 

 traversed by respiratory tubes, are true, or only desic- 

 cated, branchiae aerial gills (Ed. 1st, 1811. 3088.) 

 Wings and feet are dependent from the same ring of 

 the body, and are thus like the branchiae and feet of 

 the Crabs. Let the Crab's branchiae elongate and dry, 

 and they will thus be wings. 



3269. Since the wings are newly eliminated organs 

 of the sense of feeling, so are they here characteristic of 

 the animal, and are consequently of greater importance 

 for the purposes of division and arrangement than the 

 organs of the head, which in all the lower animals is 

 only an apparent head, and cannot therefore serve to 

 characterize groups, &c. 



3270. That the tracheae in Insects have been de- 

 veloped out of the branchiae by saccular inversion, is a 

 fact displayed in a particularly distinct manner by the 

 Scorpions and Spiders, who still possess at bottom inter- 

 nal branchial laminae, unto which, however, air instead 

 of water finds its way. It may be said, that with the ge- 

 neral conversion into horny texture, the arteries of the 

 Mussels were transmuted into internal tracheae, and the 

 branchial flabellae into external organs. Would we inter- 

 pret the body of the Insect in a strictly philosophic sense, 

 the parts must then receive very different names to what 

 they now bear. Properly speaking, in our own species 

 the thorax has no limbs, but only the neck. The upper 

 limbs are not lungs, but branchial organs, and it is the 

 cervical vertebrae, from between which nerves are sent off 

 to the arms, for it is just upon the neck also that the 

 branchiae have been left. What is termed therefore the 

 thorax in Insects, would be properly their neck. Their 



