92 SLOW LEMUR. 
these vessels are also finally distributed as in 
the upper extremity ; the cylinders wholly upon 
the muscles, and the arborescent branches on all 
the other parts. The carotid arteries do not di- 
vide into equal-sized cylinders, but are distributed 
as in the generality of animals. 
It would be of some importance in physiology 
to ascertain whether the other slow-moving Quad- 
rupeds have any peculiar arrangement of the ar- 
teries of their limbs. This sohtary fact is hardly 
sufficient for the foundation of any theoretical 
explanation of the slow movement of these mus- 
cles : if, however, it should be corroborated by 
similar circumstances in other animals, a new 
light may be thrown upon muscular motion by 
tracing a connection between the kind of action 
produced in a muscle, and the condition of its 
vascularity or supply of blood. " 
Fig. I. The arm and shoulder of the lemur tardigradus. 
a. The subclavian artery, lying upon the subsca-, 
pularis muscle. 
b. The division of the artery into equal-sized cy- 
linders. 
c. The ulnar artery proceeding ta divide in the 
ufual manner. 
Fig. 2. The trunk, from below the diaphragm, of the le- 
mur tardigradus, one of the limbs being left un- 
finished, as it appeared unnecessary to reprefent 
them both. 
a. The diaphragm. 
b. The descending aorta. 
c. c. The iliac arteries. 
d. The trunk of the inguinal artery, situated among 
the cylinders. 
c. The femoral artery under similar circumstances. 
