344 SUPPLEMENT 
more conclusive, were made by M. G. Tarenne, of whom we 
have spoken before, in 1803. If we admit the testimony of 
this gentleman, we cannot refuse to believe that snails can 
reproduce the entire head, since he assures us that the piece 
which he suddenly cut off, with very sharp-edged scissors, 
placing them perpendicularly, a little behind the large ten- 
tacula, and under the foot, contained not only the tentacula, 
the jaw, and the upper lip, but also the buccal mass altogether, 
the brain, and the anterior part of the foot. He continues 
even to assure us that snails thus mutilated, at the end of a 
year and more have reproduced a complete head; but a fact 
so extraordinary, with reference to so great a length of time, 
requires much more evidence before it can be generally re- 
ceived. Nevertheless, Spallanzani says very positively that 
the head is regenerated, whether the section be made above 
or below the brain. ‘Thus we find, that whatever re- 
pugnance we may feel in admitting this fact of the regenera- 
tion of the entire head in the helices, it is exceedingly 
difficult to deny it altogether. It took place in about two 
years after decollation, and the new head did not differ 
from the old, but in the circumstance of the skin which 
covered it being whiter and smoother. Sometimes also, there 
is a sort of furrow at its junction with the trunk. According 
to Spallanzani, it appears that the manner in which this re- 
production takes place is rather variable, and that sometimes 
it even remains incomplete. But M. Tarenne says, that 
having cut the heads off of two hundred helices, and having 
put them into a humid thicket at the extremity of a garden, 
so that they might more easily find the nutriment which was 
suitable to them, he perceived on all the individuals that he 
could find again at the end of the fine season, a new head 
somewhat resembling a coffee-berry. It had four small horns, 
a mouth, and lips. At the end of the following summer the 
heads were perfectly reproduced, except that the skin was 
