ON ANN^ELIDA. 113 



blooded, which was changed by M. Lamarck into that of An- 

 nelida. The generic characters of the lumbrici are : body elon- 

 gated, very extensible, attenuated at the two extremities, but es- 

 pecially at the anterior, composed of a great number of articula- 

 tions, having for appendages only spines or setae, forming longi- 

 tudinal striae ; mouth, terminal, simple; anus likewise terminal, 

 and longitudinal ; the organs of generation terminating tow^ards 

 the anterior third of the body, near a sort of pad or swelling, 

 more or less considerable, which may be remarked there. 



The organization of the lumbrici has been studied by 

 several persons, and among others by Willis, iledi, Mon- 

 tegre, and Sir Everard Home. Their body, perfectly 

 round, is terminated in a manner more obtuse behind than 

 in front, where it is considerably attenuated, and becomes 

 very pointed ; the furrows which divide it into articulations 

 are so much the deeper and more crowded, as they approach 

 more to the posterior extremity ; also the articulations are 

 much more marked in front than behind ; they are especially 

 so in a place situated towards the anterior third of the body, 

 where we remark an enlargement of a redder colour, formed 

 by six rings not so distinct as the rest. At the sixteenth 

 ring, at its inferior and lateral part, is a sort of ovaliform 

 tubercle, transverse, whiter than the rest of the body, which is 

 pierced by a cleft equally transverse. This is particularly 

 evident when the animal is elongated. At the thirty-sixth 

 ring we see equally on each side a part more flesh-coloured 

 than the rest, and which represents an elongated tubercle, 

 occupying the space of three rings : no trace of aperture 

 is visible there. O. Fabricius, in his description of the 

 common earth-worm, puts this pad at the twenty-seventh and 

 twenty-eighth rings, and says that in front, that is to say, at 

 the twenty-fourth, he has seen a pendant, soft appendage, 

 whose envelope being very thin, suffered to escape a limpid 

 fluid, through an orifice by which it was pierced ; at the 



VOL. XIII. I 



