ANIMAL REPRODUCTIONS. 321 
«whether the trunk is entirely deprived of the 
thead (1). . The anterior part of fuch a trunk, 
drawn from life, is reprefented, fig. 2, and the 
profile, fig. 3. plate 8. Jt is evident that the 
Aleth is powerfully contra€ted to-clofe the enor- 
mous -wound. 
The vifcous matter, exuding after decapitation, 
forms a thin whitith operculum, which complete- 
dy obftruéts the mouth of the fhell. Two of 
thefe opercula are frequently formed, one fituated 
above the other, fometimes there are three; the 
exterior of which is near the edge of the open- 
ing, and the inmoft more or lefs within the fhell. 
Though.the decapitated {nail can reproduce 
feveral opercula, the vifcous fluid is gradually ex- 
haufted, and the fhell at laft remains open, or 
nearly fo, becaufe the animal, being incapable of 
feeding while deprived of the head, -cannot re- 
pair the continual lofs of this kind of varnifh. It 
infenfibly becomes emaciated, which is evident 
Vor. IL x by 
(1) It may happen that the {nail does not extend fo 
much as would be defirable, or as is neceflary for judging 
-of the progrefs of reprodudtion, but it is only requifite to 
take the fhell between the fingers, after removing it from 
the water, and the animal will foon extend as much as 
poffible. Great care muft be obferved to avoid touching 
the fnail, becaufe the moit gentle motion makes it retire 
‘dato its shell. sak | 
