64 Experiments on Marine Testaceous Animals. 



Spring and autumn are the most proper seasons for these 

 observations. It is requisite for the observer to be endowed 

 with great patience, these animals being very sensitive to the 

 least touch ; for which reason it is extremely difficult to cut 

 off the part wished to be reproduced : and it has frequently 

 happened, that at the slightest touch of the sharp instrument, 

 they drew in immediately, and retired to the innermost part 

 of their shells, and I was obliged to wait for a more favorable 

 moment, on their re-appearance. 



The shell must be placed in a firm position, and the animal 

 watched, until it presents the part you desire to operate upon. 

 The operation must be performed with skill and agility, other- 

 wise the opportunity is lost : the greatest difficulty, however, 

 is with the smaller animals. 



On the 8^ August, 1836, I procured a Triton nodiferum, 

 Lam. about eight inches long ; cut off one of the tentacula, 

 with the eye, which is situated on the external side of its base. 

 I also broke off a piece of the shell ; and placed the whole in 

 a cage. 



\bth August. Examined it, but saw no appearance of an 

 attempt at reparation, and then replaced it in the cage, fear- 

 ing my hopes would not be realized. 



28th August. Re-examined it, and to my great satisfac- 

 tion found that the eye and tentaculum had appeared, to the 

 length of about six lines ; that which had been cut off mea- 

 sured fourteen lines. The shell was nearly repaired, although 

 irregular. 



12th September. Made similar experiments with another 

 Triton, of w r hich a drawing was made, when the reproduced 

 tentaculum measured three lines. 



6th September. Took ten specimens of Murex trunculus, 

 from fourteen to eighteen lines long ; cut off their heads and 

 tore off their operculum. 



10th October. Found eight alive, six of which had repro- 

 duced their operculum, and four their heads and tentacula. 



Wth September. Cut off the spout and tentacula of a Co- 

 nns, fourteen lines long. 



8th October. Visited it, and found that it had reproduced 

 both, perfectly similar to the others. 



6th September. Made similar experiments on two other 

 specimens of Triton nodiferum, and on the Fusus lignarius, 

 with a result similar to the preceding. 



To prove my observations, I sent to the Genoese Academy 

 some of the animals alive, and others preserved in spirits of 

 wine, to correspond with all that I assert in this article, as 

 having determined by experiment. 



