■ Ve-rtebkal animals. I6t 



I. 

 VERTEBRATA. 



Vei'tehral Animah'. 

 Character. — Animals furnished with a skull and 

 vertebral colbmn for the protection of the 

 brain and spinal marrow *. 



Description.— The properties Avhicli the vertebral ani- 

 inals possess in common, are numerous, and clearly indicate 

 the unity of the plan according to which they have been 

 constructed. In reference to the nervous system, indeed, 

 a conformity of character here prevails, which is not obser- 

 vable in that, or any other system of organs among the in- 

 vertebral tribes. 



1. Cutaneous System. — The skin here appears in its 

 most perfect state. It exhibits the cuticle, the mucous 

 web, and the corium, in all cases ; nor are the muscular 

 and cellular webs often wanting. 



2. Osseous System. — The bones, which are destined for 

 the support of the body, always abound in phosphate of 

 lime, and they increase in size, by the expansion of their 

 cartilaginous basis. The basis of the skeleton may be re- 

 garded as the skull, to which are joined the bones of the 

 face, on one quarter, and the spine on another. The spine 

 consists of vertebras, with a groove or canal on the dorsal 

 aspect, for the reception of the spinal marrow. The limbs, or 



• It may be objected to this primary division of animals into Vertebral 

 and Invertebral, that the characters which are employed in their.discrimina- 

 tion, are derived from modifications merely of the nervous system, instead of 

 depending on the presence and absence of particular organs. It would cer- 

 tainly appear to be more consonant with the principles of classification which 

 have been recommended, to divide animals into such as had apparent nerves, 

 and such as were destitute of apparent nerves. Still, however, as there is no 

 animal without a nervous system, it would only he employing a different mo- 

 dification of the same organs, and one, the hmits of which, arc less distinctly 

 defined. 



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