upon tbe Structure and Oeconomy of Tanie. PAT 
fibres are not at all vafcular, which fhews that the actions of 
mufcles are not neceffarily connected with vafcularity. 
The head of this animal is compofed of the fame kind of 
materials as the other parts of its body; it has a rounded opening’ 
at its.extremity, which is confidered to be its mouth. See TAB. 25. 
fig. 1, 2. This opening is continued by a fhort duét into two canals; 
thefe canals país round every joint of the animal's body, and con- 
vey the aliment, fig. 3. Surrounding the opening of the mouth 
are placed a number of projecting radii, which are of a fibrous 
texture, whofe direction is longitudinal. Thefe radii appear to ferve 
the purpofe of tentacula for fixing the orifice of the mouth, as 
well as that of mufcles to expand the cavity of the mouth, from 
their being inferted along the brim of that opening: fee fig. 2. 
After the rounded extremity or head has been narrowed into 
the neck, as is reprefented in fig. 2, the lower part becomes 
flatted, and has two fmall tubercles placed upon each flatted fi de; 
the tubercles are concave in the middle, and appear deftined to 
ferve the purpofe of fuckers for attaching the head more effeétu- 
ally. "The internal ftru&ure of the joints compofing the body 
of this animal, is partly vafcular, and partiy cellular; the fub- 
ftance itfelf is white, and fomewhat refembles in its texture the 
coagulable lymph of the human blood. The alimentary canal 
pañlés along each fide of the animal, fending a crofs canal over the 
bottom of each joint, which connects the two lateral cina Eod 
ther. See fig. 3. | ; 
I have ots infa three feet in length of thefe canals with’ 
coloured fize, by a fingle pufh with a frail fyringe. The injec- 
tion will not however pafs from below upwards along thefe canals; 
Icould never make it go in this direction. beyond two joints, and 
it appeared to be ftopped by valves in the lateral canals, fituated 
K-k 2 : immediately 
