SECTION IV. 



* 



THE CLASS OF VERMES OR ANNULATA OR WORMS. 



SUB-SECTION I. 



* 



THE WORMS COXSIDERED AS A CLASS. 



NATURALISTS are not fully agreed as to the limits of the 

 Class of Worms.* 



It may be stated, however, that "Worms are the lowest 



of all the Articulates that is, the simplest expression of 

 the Articulate plan. It may be stated, in general terms, 

 that they are much elongated, and similar in form through- 

 out their whole extent. The head segments in many 

 cases, however, are quite different from the others, and 

 more or less highly specialized. 



As already implied, there is no division of the body 

 into regions, as we have seen in Insects and in Crustaceans ; 

 and none of the Worms have jointed legs, as in those 

 classes. In many cases, however, they have tubercles, 



* Professor Edward S. Morse ( On the Systematic Position of the Brachiopoda), 

 after a long series of investigations, has come to the conclusion "that in 

 every point of their structure the Brachiopoda are true worms, with possi- 

 bly some affinities to the Crustacea, and that they have no relations to the 

 Mollusca, save what many other worms may possess in common with 

 them." Professor Morse is supported in this view by many of the ablest 

 investigators of the present clay. 



But as the subject is still under discussion, we have decided that it will 

 be better, for our present purposes, to describe the Brachiopoda in their 

 old place under the Mollusca (see p. 432). 



Every student, however, should read the Paper cited above, where he 

 will find, clearly presented, the reasons why Professor Morse regards the 

 Brachiopods as true Vermes. 



