ON ANNELIDA. 
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 towards 
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, Redi, 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 
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