376 Zoological Collections. Invertebrata. 



according to M. Morren, the latter should be still farther reduced ; and he 

 founds his opinion on the obvious changes which age, and even season, 

 produces in the worm. The consideration of the cUtellmn, on which the 

 principal character depends, is of no real importance, this organ being 

 modified in a thousand ways, and sometimes entirely disappearing. M. 

 Morren particularly describes these changes, and gives a plate of them. 

 The principal differences occur in the organ being more or less extended ; 

 in its comprehending a greater or less number of rings ; in its form, and in 

 its variable colour. M. de Blainville thinks that the number of the rings 

 in the earthworm varies from 100 to 140; Linnoeus, from 117 to 133; 

 Cuvier, from 120 to an indeterminate number; Fabricius numbers them 

 at 143; M. Morren thinks that there are from 120 to 150; and their 

 dimension is subject to as many varieties. Internally they are not so easily 

 distinguished, as they are covered by the muscles ; each of them is separated 

 from the adjoining one by a membrane, which corresponds to an internal 

 diaphragm, and which surrounds the intestinal canal. 



Properly speaking, the Lumhricus has no head ; the third, fourth, or fifth 

 ring contains the brain, or principal ganglion. The mouth is composed of 

 two lips, which move from above downwards, and present very remarkable 

 varieties ; the upper lip is very large compared with the lower, so that in the 

 prehension of food, it is the principal agent, rolling backwards the little pieces 

 of earth. In the perforation of holes, also, it is called into exercise, and it 

 then moves from below upwards, and thus throws aside the earth, as the 

 trunk, or anterior part of the body, advances like a wedge into the ground. . 



Willis discovered pores in the back, which, he said, lead into the tracheaa. 

 MM. Montegre and Carus adopt this opinion, whilst MM. Home and 

 De Blainville admit two lateral series of pores. M. Morren only finds a single 

 dorsal series, beginning about the twelfth or nineteenth ring ; and these 

 he supposes to be the proper orifices of internal pulmonary sacs. Willis says 

 that he introduced into these pores the extremity of a tube, and filled them 

 with air ; M. de Blainville thinks them destined to give exit to a secreted 

 fluid, and thinks that the respiratory function belongs to the whole skin. 



M. Savigny has particularly studied the locomotive organs of the Anne- 

 lides ; and all naturalists are acquainted with his organological classification 

 of these parts. M. Savigny's views are very important, for it appears that 

 the characters drawn from the bristles are, in the genus Lumhricus, the 

 best adapted for the distinction of species. We owe the discovery of these 

 organs to our countryman Ray, in what he called the apodal worms. M. 

 Savigny gives the name of foot to a pair of these bristles ; but M. Morren 

 remarks, that we cannot comprehend, under a single denomination, organs 

 which are actually distinct : he recognizes a double series, each composed 

 of two rows of bristles, which are internal or external, and ventral or 

 dorsal, according as they are viewed. Each bristle has its base attached to 

 the bottom of a fleshy cone, which gives attachment to strong retracting 

 muscles ; its summit is a little curved, and the whole series is itself more 

 or less arched ; it is calcareo-horny, homogeneous, yellowish, and brilliant. 

 These organs serve to support the animal in locomotion, and to fix it to the 

 ground when it is copulating. 



Two tubercles are found on the young worms, and four on aged indivi- 

 duals, each having a transverse fissure. The anterior occupy the sixteenth 

 and seventeenth ring, or the one the sixteenth and the other the seventeenth \ 

 and the posterior the twenty-seventh and the twenty-eighth ring together, or 

 the one the first and the other the second. The anterior of these papillae 

 correspond to the ovaries, the posterior to the stomach, or adjoining parts ; 

 the first serve for generation ; the use of the second is unknown. These 

 parts disappear in winter. Otho Fabricius, in his Fauna Groenlandica, 

 noticed that the earthworms have sometimes a peculiar appendage on the 

 twenty-fourth ring ; he took it for a kind of penis. It seems that Montegre 



