290 ZOOPHYTES. 



LESSON 102. 



Vermes and Zoophytes. I 



Tentac'ula, often called feelers ; organs supplying the place of 

 hands and arms to some animals, and intended also for feeling. 

 (Singular, Tentaculum.) 



The term Ver'mes 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. Their bodies are of a cylindrical, 

 elongated shape, divided into a great number of rings. In 

 some species, certain black points appear around the head, 

 which have been supposed to be eyes, but this is doubtful. 

 They are the only invertebral animals which have red blood. 

 It circulates in a double system of vessels, but there is no 

 distinct fleshy heart to give it motion. They breathe by 

 means of gills, which are sometimes within and sometimes 

 without their bodies. They have no limbs, but on each of 

 the rings of which their bodies are composed, are little 

 spines or bristly projections which answer in some sort the 

 purpose of feet. All, except tlie earthworm, inhabit the 

 water. Many of them bury themselves in the sand ; some 

 form themselves a sort of tube or habitation of sand, or other 

 materials ; and others exude from their surfaces a calcareous 

 matter, which produces a shell around them. When cut 

 through the middle, each portion becomes a distinct in- 

 dividuals 



There are several species of the leech, of which the me- 

 dicinal leech is the most valuable. It has three jaws or ra- 

 ther lancets, with which it pierces the skin of animals, in 

 order to draw their blood. Its tail is furnished with a shal- 

 low cup, by which it is able to fix itself firmly to different 

 objects, while obtaining its nourishment ; and by means of 

 the same organ it mov^s from place to place. 



The class of Zo'ophytes is the last division of the animal 

 kingdom, and the lowest in the scale of the animated crea- 

 tion. It includes an immense number of individuals but 

 imperfectly known, and having but few points of resem- 

 blance and connexion with one another. In general, they 

 have no nervous system, no complete vascular circulation, 



