62 MEMOIRS OF 



a certain number of rings, the teguments of which are 

 sometimes hard, and at others soft, but to the interior of 

 which the muscles are always attached. The trunk often 

 bears articulated members on its sides, but is as often with- 

 out. These are the ai-ticulated animals, and it is among 

 them that we observe the passage of the circulation in 

 closed vessels, or nutrition by imbibition, and the correspond- 

 ing passage of respiration in the circumscribed organs call- 

 ed tracheae, or aerial vessels spread over the whole of the 

 body by means of which it is performed. Like the second 

 form, there is but one family which possesses the organs 

 of hearing, and those of the taste and sight are chiefly de- 

 veloped. If they have any jaws they are always lateral. 

 The fourth form embraces all the animals known under 

 the name of zoophytes, and is called that of radiated ani- 

 mals. In all the preceding, the organs of movement, and 

 the senses, are symmetrically disposed on the two sides of 

 an axis ; they have a posterior, and an anterior face of 

 dissimilar appearance. But in those now^ mentioned, they 

 are as if composed of rays round a centre, even when 

 there are but two series of these rays, for then the two 

 faces are alike. They approach the homogeneity of plants ; 

 they have no very distinct nervous system, nor particular 

 organs for the senses. In some there are scarcely any 

 vestiges of cumulation ; their respiratory organs are almost 

 always on the surface of their bodies ; the greater number 

 have but one bag without issue for an intestine, and the 

 last families only present a sort of homogeneous pulp, 

 moveable, and sensible to the touch." Here I must again 

 impress on the reader, that M. Cuvier's first great discovery 

 was the necessity of separating this last form of animals 

 from the general mass of insects and worms, having read 

 his Memoir, pointing out the characters and limits of mol- 

 lusca, echinodermes, and zoophytes, to the Society of ^sa- 

 tural History in Paris, on the lOth of May, 1795. From 

 this he ascended to animals of more complicated form, for 

 it is only a man of narrow mind that can treat any part 

 of natural history with contempt. All others will see in it 

 •• a continuance of that command given to Adam, to see, 

 to name, and to use the creatures put under his control.*' 

 No branch of it, however trifling, but may be ennobled 



