tlO tNVERXEBRATEB 



CHAPTEB XVIIl. 



DIVISION II.— INVERTEBRATES. 



CLASS VIII. — WORMS. CLASS IX. — ZOOPHYTE S. 



The term Vermes or Worms, says Dr. Ware, in his Intro- 

 duction to " Smellie's Philosophy of Natural History," has been 

 used with great vagueness in natural history, and employed to 

 designate animals to which the name was not appropriate. It is 

 now, however, more restricted in its application, and is made to 

 include only a small class of animals, which have some circum- 

 stances in common with each of the three classes last described, 

 but still not exactly resembling any. They are sometimes called, 

 by way of distinction, Worms with red blood, as they are the only 

 invertebral animals which have red blood ; and sometimes Anne- 

 liJes, from the structure of their body, which is of a cylindrical, 

 elongated shape, divided into a great number of rings. 



Their nervous system resembles that of the Insects and 

 Crustacea. Their organs of sense consist merely in some fleshy 

 tentacula, which surround the mouth, and answer the purpose of 

 feeling and touching. In some species, certain black points appear 

 around the head, which have been supposed to be eyes, but this 

 is doubtful. Their blood is nearly of the color of that of the ver- 

 tebral animals, but not of so bright a red. It circulates, in a 

 double system of vessels, but there is no distinct, fleshy heart to 

 give it motion. They breathe by means of branchisB, which are 

 sometimes within and sometimes without their bodies. They have 

 no limbs, but on each of the rings, of which their bodies are com- 

 posed, are little bristly projections, which answer in some sort the 

 purpose of feet. Their mouths are sometimes armed with jaws, 

 and sometimes consist in a mere tube or sucker. 



Their bodies are soft and compressible. All, except the 

 earth-worm, inhabit the water. Many of them bury themselves 



