358 ANIMAL REPRODUCTIONS, 
them had made but little progrefs, and fhewed 
only the origin of a fingle horn : Two eye-horns 
had protruded in one alone, at leaft a line and 
a third in length, and the optic nerves fo large, 
or vifible, that they feemed to darken the great- 
eft part of the horns; but the {mall ones, the 
lips, and the other parts of the mouth, did not 
yet appear. ‘This {nail obftinately remained in 
the fhell, though immerfed in water more than . 
two hours. Sufpecting its death, I had taken it 
out ; and, not before an interval of feveral hours, 
‘was i agreeably furprifed, by feemg it proceed 
from its fhell of its own accord, and ee its 
new produétions before me. 
In another Memoir, I fhall give the biftory of 
thefe eight fnails. 
After experiments on {nails of the fmalleft fpe- 
cies, it was proper to make them on the largeft. 
This I began to execute, 24 May 1780, on twelve 
of the largeft that are found with us. We 
may judge of their fize, compared with the {nails 
which have hitherto been the fubjeét of this and 
the preceding memoir, when the diameter of the 
mouth of the fhell of the latter was at leaft nine- 
teen lines, and that of others, only four or five. 
in a few weeks, half my fnails died, and 
exhaled an exceflively foetid odour. On 13 Au- 
guit, 1 immerfed the fix furviving. They pro- 
ceeded from their thells ; 3 and I faw that the im- 
menie 
