226 LKCTURE XI. 



called " red-blooded worms," " vers a sang rouge," and " anellides," 

 by the French naturalists ; in Latin Annulata, from annulus, a little 

 ring, because the entire body of these worms is made up of a suc- 

 cession of segments like little rings. 



The mind is not easily liberated from the sway of opinions that 

 have long been held as authoritative : although Cuvier recognised 

 the exaggerated importance of the zoological character derived by 

 Aristotle from the colour of the blood, yet the judgment of the great 

 modern reformer of zoology continued to be so far biassed by that cha- 

 racter, that, in his latest edition of the " Regne Animal," he continued 

 to place the anellids, on account of the colour of their circulating 

 fluid, at the head of the articulate series, above the crustaceans, 

 above the arachnidans, and above the insects, whose transitory larval 

 condition these apodal worms seem permanently to represent. 



The body of an anellid is always long, soft, and subdivided into a 

 number of segments, for the most part closely resembling or identical 

 T?-ith each other. In many species the first segment is so slightly 

 modified as scarcely to deserve the name of head ; in others it is the 

 seat of higher senses and more varied functions, and is at once recog- 

 nisable as the cephalic segment. 



In the lowest forms of the Annulata the locomotive instruments 

 are suctorial discs, and the alimentary canal adheres to the integument, 

 as in the Trematode worms ; but the suckers are always two in 

 number, and are terminal in position. The species next in order 

 have the alimentary canal less extensively attached, and have stiff 



hairs or minute hooks projecting from 

 each segment. In the higher Anellides 

 the alimentary canal is freely suspended 

 in an abdominal cavity, and most of 

 the species have on each side of the 

 body a long row of tufts of bristles, sup- 

 ported upon fleshy tubercles, which in- 

 dicate the rudiments of lateral and 

 symmetrical locomotive members (Jig- 

 101 .) There are often two such organs, 

 placed one (a) above the other (i), 

 on each side of the segments of the 

 body. In some species the two setigerous tubei'cles are confluent, 



rvberrimo Uquoro plenus, qui mihi cordis sui trunci systematis vasculosi vice fungi 

 vidctur." 



" Vas rubrum intcstinalem tractum concomitans in hac Ncrcidc (iV. conchtlega) 

 Deque ac cylindraria inveni," 



Anatome Ncreidis Bclgicae, in "Miscellanea Zoologica," v. pp. 128, 129. (1766.) 



