194 BRITISH ANNELIDS. 



Let me first claim the reader's indulgence for a moment while I 

 attempt a brief description of the class of animals to which the 

 earthworm belongs. If we admit that every member of the animal 

 kingdom must belong either to the vertebrates or the invertebrates 

 — just as every plant must be a phanerogam or a cryptogam — then we 

 know that worms are invertebrates, because they are boneless. Now 

 the invertebrate animals fall into a number of sub-kingdoms, the 

 names of which I need not detail. One of these divisions, however, 

 must include worms, and to it the name of Annulosa, or Articulata, 

 is applied. The latter term, invented by Cuvier to represent 

 this sub-kingdom of animate nature, is now usually replaced by 

 the former ; and the Annulose or articulated animals are again 

 subdivided into smaller groups. One of these bears the name 

 of Annelids, the members of which are normally distinguished 

 by the possession of a jointed body and a double nerve-chain on the 

 ventral or under surface of the body. In addition to the earth- 

 worms, there are also included in this class the leeches and freshwater 

 worms on the one hand, and the marine worms on the other. 



Not one of these groups is well known. There are numerous 

 freshwater worms in our streams and stagnant waters whose life- 

 history has never been carefully worked out by any British naturalist 

 trained in the new school of biology, while the distribution of the 

 leeches is almost unknown. Some attention has been given of late 

 years by the marine biologist, to the curious and surpassingly 

 interesting annelids found on our shores, but the results of their 

 researches are not in the hands of the public. Under these circum- 

 stances it seems eminently desirable that something should be done 

 to put us on a level with our continental and American fellow- 

 workers in this department of science. 



While I shall hope eventually to deal with each of the groups 

 included among the annelids, it will be necessary for the present to 

 confine attention entirely to that group which is at once the most 

 widely distributed and the most easily worked — the Earthworms or 

 Oligochsetes. This group of animals may be described as pre- 

 eminently domestic. By this I mean, that, wherever man is found, 

 there will the worms be also ; w^hereas they are almost entirely absent 

 from our broad moorlands and bleak mountains, except where the 

 cattle graze, and the collie seeks up the sheep. Their distribution is 

 very wide. The following hints will afford the collector all the 

 information he needs for starting him in his pursuit, experience 



