339 ANIMAL REPRODUCTIONS. 
for equivocal what was a real reproduction: of 
perhaps they thought the {nails ftill alive were 
dead. In this cafe, it is requifite to have much 
patience, and, above all, to defpair of nothing. I 
do not {peak of the diverfities which the difference 
of fpecies might occafion in the refult of the 
experiments made by thefe celebrated perfons ; 
for there is reafon to fuppofe, that among the im- 
menfe number of {nails on which they have ope- 
rated, fome were of the fame fpecies as mine. 
Neither do I fpeak of the diverfities that might 
arife from the difference of climate; for that of 
Paris is very little different from ours. There- 
fore I entreat thefe able naturalifts not to be dif- 
couraged, and to refume a fubje@ fo pregnant 
with new faéts, and one which cannot be too 
deeply inveftigated. They poffefs far more in- 
formation, talents, and ability, than are neceflary 
to fucceed in experiments of this nature: and I 
may predi& the moft complete fuccefs if they will 
not be difcouraged, and if they will proceed in 
the manner I have done.. 
M. Adanfon wrote to me concerning his own 
experiments, 30 July 1769. ‘ I begin to have a 
‘ philofophic doubt concerning the regeneration 
‘ of the head, horns, and jaws of {nails. My exe 
‘ periments, diverfified to infinity for above a 
‘year, on fourteen or fifteen hundred {nails of 
‘ different fpecies, convince me that my doubt has 
‘ foundation. 
