116 SUPPLEMENT 



of those other pairs of white vesiculae, the posterior of which 

 is thicker and more oblong. It would seem that these last 

 communicate with the exterior by the vertical clefts which 

 we have observed on each side of the sixteenth ring. It is a 

 query whether the posterior bodies are the ovaries, the eggs 

 from which, previous to issuing forth externally, should pass 

 through the anterior vesicles, that would thus perform on 

 them the office of spermatic organs. Of this we must be the 

 less certain, as Montegre assures us that the young ones, 

 which come forth in the living state, do so by the anus, and 

 that the eggs from which they proceed have descended be- 

 tween the external envelope, and the intestinal canal, as far 

 as the circumference of the rectum, a disposition which is, 

 to say the least of it, very singular. It seems, however, 

 quite certain that the lumbrici are ovoviviparous. 



The nervous system of the lumbrici is composed of a brain 

 extremely small, situated above the mouth, and of a gastric, 

 or abdominal cord, which is formed by a series of a great 

 number of small ganglia, much crowded, one against the 

 other. 



The lumbrici cannot be supposed to taste, smell, see, or 

 hear, in any wise, since they have no specific organ of sense. 

 But, in compensation, their touch appears to be extremely 

 delicate. Accordingly, it is sufficient to strike, or even slightly 

 to stir the earth which they inhabit, to make them come out 

 quickly. The mucous nature of their skin causes them to be 

 partial to humidity, whether in the earth or atmosphere. 

 They are, therefore, much afraid of the drying action of 

 light, sun, and air. If, by any cause, they find themselves 

 exposed to it they quickly endeavour to withdraw from its 

 influence by sinking into the earth, or getting under some 

 shelter, and if they cannot do so they soon dry up, and are 

 deprived of life. They move with tolerable swiftness on the 

 surface of the earth, by the alternate extension and approxi- 



