WORMS 69 



eluded in the division Vermes or Worms, nearly 

 everything except the vertebrates and insects. 



This assemblage would have been more cor- 

 rectly styled if instead of "Vermes" it had been 

 described as " animals unsorted." Subsequent 

 zoologists have by degrees picked out and sepa- 

 rated from the Vermes first one group of animals 

 and then another. But the process is still going 

 on, and several of the groups which are still 

 classed under the name of " worms " might, with 

 very great justification, be separated from each 

 other ; it is custom, rather than family resem- 

 blance, that accounts for their being retained 

 under one heading. 



Widely although the various " worms " may 

 differ from one another, one thing may be stated 

 regarding the most of them, and that is, that 

 they " crawl " ; that is to say, they move along 

 by means of successive contractions of successive 

 parts of the muscular wall of their elongated 

 bodies. This " crawling " mode of progress is 

 the chief thing involved in the popular idea of 

 a worm; but the popular definition of a worm 

 includes also the larvae of insects, such as cater- 

 pillars and beetle-grubs. The latter, it must be 

 noted, crawl with the assistance of legs, while the 

 true worms crawl without any such assistance. 

 Any adornments that they may possess, what- 

 ever else they may be, are not legs. 



The worms were formerly included along with 

 the insects and lobsters, in a division called An- 

 nulosa, or Ring-bodied animals, but it has now 

 long been recognised that the latter are worthy 

 of a division to themselves. It will easily be 

 seen, however, that the term Ring-bodied animals 

 is very appropriate to all of them. If we look at 



