502 BIOLOGY. 



organs of the head, or rather are the head itself; the 

 Tegumental animals are therefore devoid of a true head. 

 They only possess such an one, in so far as it is deter- 

 mined by the tegument and nervous sense, by the rnouth 

 and the eyes. 



These animals are what have been called Inver- 

 tebrata, a name which is, however, defective, from its 

 indicating the absence of one part only or of a single 

 animal system, while the word flesh comprehends bones, 

 muscles, and nervous mass ; they are asarcose animals. 

 But even this last appellation is not correct, because it 

 is negative. Their positive system, or that under which 

 they actually exist, is the tegument ; so that the name 

 of Dermatozoa or Sensitive animals, is the only proper one. 



As the tegument includes the viscera and forms there- 

 fore the trunk alone, they may thus also be designated 

 Trunk-animals. 



Second Province. Sarcozoa. 



3104. As in the animal body, bones, muscles, and en- 

 cephalic system are suddenly associated with the tegu- 

 mental system ; so also does a second series of animals, 

 having these systems, suddenly originate. Now, as the 

 first formation of the osseous system is the vertebra, so 

 all these animals have, as is generally understood, a ver- 

 tebral column, and are on that account indeed Verte- 

 brata ; but, they are much more than this, and hence the 

 title is of too limited a character. Besides there are 

 among them animals, in which only the chorda dorsalis 

 is present, without the ring of the vertebral body being 

 formed around it. 



Along with the animal systems the head is for the first 

 time developed with its organs of sense Cephalic animals. 



These animals have consequently, in addition to the 

 general sense of feeling, a true tongue, nose, ears, and 

 eyes Cephalasthetic animals. 



B. ANIMAL CIRCLES. 



3105. Animal Circles are representations of entire 

 anatomical systems as self-substantial bodies. 



