ANIMAL REPRODUCTIONS. 223 
rather pear-fhaped figure below. Thefe nerves 
have mufcles, by whofe agtion, at the animal’s 
pleafure, both large and {mall horns are retracted 
and concealed in the body; and the eyes, by 
this means, are alfo concealed, to be fecure from 
external injury. 
On removing the brain, the cefophagus is dif- 
covered, which is membranaceous, and furrowed 
by the fineft longitudinal ridges of livid afh co- 
jour. The fides are extremely fmooth ; and it 
contraéts as it gradually approaches the mouth, 
This opening, by which the fnail feeds, is pro- 
vided above with a palate and a callous jaw, to 
which is firmly fixed a tooth of a corneous fub- 
ftance, chefnut coloured and fhaped like a cref- 
cent, terminated by fome fharp prominent points, 
which form, in a certain manner, fo many moft mi- 
nute teeth, though, properly fpeaking, the animal 
has only one; and this is therefore the {nail’s only 
tooth. Inthe lower part of the mouth is the 
tongue, provided with a {mall kind of corneous 
fubftance at the extremity; and the root is fixed 
in a hollow femicircular cartilage. Thefe are the 
chief parts of the head, omitting a number of 
mufcles moving them: and as the defcription of 
thefe does not feem important, I fhall negleé 
it altogether, without committing any fault by 
the omiffion. 
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