ai4 ON THE CLASSES OF THE 



perfect. It has indeed been long since observed that the 

 whole internal anatomy, and in particular the organs of 

 respiration and circulation in the Mollusca and Vertehrata, 

 differ entirely from the structure of the divisions of 

 Acrita and Radiata, and from that of the greatest part of 

 the Annulosa. Now, in the preceding chapter we have seen 

 that the only method by which the unnatural interruption 

 oi ih.e Annulosa and Fertebrata by the Mollusca may be 

 avoided, is one which necessarily places the last mentioned 

 group nearer in general construction than the Annulosa 

 to the point of union between the two kingdoms of orga- 

 nized nature, that is, to the lowest of animals. It follows 

 therefore, that though they undoubtedly possess a very com- 

 plete system of respiration and circulation, the Mollusca 

 are inferior in the scale of nature to the Annulosa. 



If we are to judge of the rank of the Vertebrata by the 

 distance at which they are removed from inorganic mat- 

 ter, or, which is the same thing, from the confines of the 

 vegetable and animal kingdoms, some of the Annulosa 

 ought to be found to possess an organization quite as in- 

 tricate as the animals Avith vertebrae. This principle, I am 

 aware, may be objected to • and indeed it is so very diffi- 

 cult to compare with one another two divisions of ani- 

 mals which differ completely in their anatomical structure, 

 whose very senses, for aught we know, are of totally di- 

 stinct natures, that it becomes useless to attack or defend 

 the propriety of such comparisons. No animal displays so 

 much docihty for general purposes as some of those which 

 are vertebrated ; nor does any display instinctively such 

 wisdom for a particular purpose as an insect. No animal 

 can be compared to such as are Annulose for strength and 

 swiftness in proportion to their size, for perseverance and 



