320 APPENDIX. 



was pleased with the success he had in experimenting on the Nais 

 or StyJaria of Lamarck, of which he saw the half become a perfect 

 animal in ten or twelve days, notwithstanding the great number of 

 external organs and the number of feet which were to be remade ; 

 and notwithstanding that the singular dart or proboscis, which pro- 

 jects in front of the head, had to be recreated with all its original 

 delicacy, and made to shoot out from a segment which, originally, 

 had its position in the centre of the body*. 



As Bonnet had done, so did Reaumur experiment also on earth- 

 worms. He cut individuals into two unequal halves, the anterior 

 being made considerably shorter than the posterior. The worm 

 seemed to suifer little from the division. Often in less than two 

 days, the anterior portion had become a perfect animal, so far at 

 least as the possession of a structure alike to the original was con- 

 cerned, for it is true that the new tail has then by no means acquired 

 the size nor length of the old one ; but, by slow degrees, ring after 

 ring continued to be developed, and, after the lapse of several months, 

 the new had become the equal of the part which had been lopped 

 away. The reproduction of the anterior portion from the posterior 

 was effected with comparative slowness, for three or four months were 

 required for the task ; and, in many instances, the experiment was 

 unsuccessful, especially in the common species, two others aUied to 

 it being more gifted v/ith the power of regermination. But neither 

 the slowness of the growth, nor the precariousness of the experiment, 

 does in any way lessen the miracle. In the latter case, especially, 

 there is not merely a production of rings very similar to each other 

 — ring evolving ring, — but there is the making anew of a head with 

 its nerves of sense, and with all the curious mechanism of a mouth ; 

 — there is the regrowth of organs, male and female, on the same in- 

 dividual, and of no ordinary complication ; — and there are new organs 

 wherewith the animal has to digest and breathe, &c. No wonder 

 that physiologists were startled at such phsenomena, and were induced 

 to indulge in speculations of a curious kind as to the divisibility of 

 the living principle, and the connexion between material organization 

 and spiritual essence. 



Spallanzani, the friend of M. Bormet, and the most celebrated 

 experimentalist of his age, pursued the inquiry, and extended it's 

 scope. So far as the worms were concerned, he confirmed the facts 

 announced by his friend as to the power of reproduction in severed 

 parts ; but one conclusion arrived at was at variance with an axiom 

 of Bonnet's. " If the two ends are cut off a worm," says Mr. Dalyell, 

 epitomizing Spallanzani's experiments, " the middle piece will become 

 a perfect animal ; but the head will not germinate from what we 

 should suppose the natural place, that is, the anterior part ; on the 

 contrary, it proceeds from the portion that was next the original 



* Reaumur says that he did not succeed in making the Nereides, from 7 to 8 

 inches long, reproduce their amputated organs ; " mais les essais n'ont peut-etre 

 pas ete encore assez repetes ni assez suivis." — Pre/, lix. See Williams, Rep. 

 1851, p. 249. 



