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renne, the author of a little treatise called Cochlioperie, assures us of this. 

 He employs the blood of the animal, which he obtains by pricking it with 

 a sharp-pointed instrument, and puts it in the shape of a cataplasm on the 

 cushion of the bandage. 



Physiologists have made use of these animals to prove that reproduction 

 does not confine itself to unimportant parts, or to animals of a very low rank. 

 The beautiful experiments of Trembley, on green hydra; or fresh water po- 

 lypi, had put it beyond doubt, that in this degree of organisation an animal 

 could not only reproduce the different parts of its body, but that, if it were 

 cut in pieces, each piece would become a perfect animal : he even caused 

 six and seven heads to spring from a simple body, by dividing the animal 

 into as many longitudinal shreds. The following year (in 1745), Bonnet, 

 wishing to repeat the experiments of Trembley, and being unable to procure 

 the green hydrse, tried if fresh water worms, a species of Nats, could not 

 also reproduce the parts which were cut off. He cut the body into 26 parts, 

 and each part reproduced a complete animal. This faculty of reproduction 

 when mutilated, was also demonstrated in the Actinia; , by the Abbe Dicque- 

 mare ; who shewed that their bodies might be divided into a considerable 

 number of parts, if a part of the mouth were left on each shred. . In 1764 

 Boscovisch announced, in a letter to Lacondamine, that snails, when their 

 heads were cut off, could reproduce others entirely similar, as the experi- 

 ments of the Abbe Spallanzani had proved. Some experiments on the same 

 subject, even more conclusive than those of Lavoisier, SchoefFer, Bonnet, 

 Mulier, etc. were made by M. G. Tarenne, who published them in 1808. 

 They proved that snails can reproduce their entire head, since he assures us 

 that the piece which he cut suddenly with very sharp scissars, placing them 

 perpendicularly a little behind the great tentacula and under the foot, con- 

 tained not only the tentacula, the jaw, and the upper lip, but the brain and 

 anterior part of the foot. The snails thus mutilated reproduced a complete 

 head at the end of a year or more ; and if other observers, adds M. Tarenne, 

 have not witnessed this fact, it is because they have not enabled the mutilated 

 Helix to nourish itself. Spallanzani, however, does not speak of this circum- 

 stance, and positively says that the head is regenerated whether the section 

 is made above or below the brain. The new head only differs from the old 

 by having a whiter and smoother skin ; sometimes there is a sort of fur- 

 row at its junction with the trunk. According to Spallanzani, it would 

 seem that the manner in which this reproduction is made is variable, and that 

 sometimes it remains incomplete; but Ml Tarenne says, that having cut off 

 the heads of 200 Helices, and thrown them into a damp grove at the end of 

 a garden, (that they might find their proper nourishment the more easily,) 

 at the end of the fine weather he perceived a new head, resembling a grain 

 of cofFee, on all the individuals which he could again meet with : this head 

 had four small horns, a mouth, and lips. At the end of the following sum- 

 mer the heads were perfectly reproduced, with the difference only of the 

 skin being smooth or cicatrised. Although Spallanzani has given fewer de- 

 tails than M. Tarenne, it is clear that he had already obtained the same re- 

 sults. Still it is difficult to conceive how the nervous filaments, the muscles, 

 the vessels which have been cut in the m'ddle of their length, reaccord with 

 the portions which shoot forth from the head, which has become a sort of 

 bud; or, admitting that the regeneration proceeds from the nervous and 

 musculary filaments themselves, how the former can shoot forth and give 

 birth to the brain. For entire conviction, it is necessary to have a careful 

 dissection made of the head thus reproduced, and to compare it with that 

 which has been cut off. 



