AVES. 337 



course, in Ihe same manner as the vessels of plies the peroneal muscles posteriorly, and 



the uterus of the human subject. passes along the outer edge of the flexors of 



" There are no regular emulgent arteries in the toes to the heel, above which, and behind 



birds ; the kidneys deriving their blood from the flexor tendon, it divides, running on each 



various sources, which will be pointed out as side of the heel, and forming several articular 



they occur arteries around the joint, and communicating 



"The inferior extremity is supplied with two with the other branch, and with the anterior 



arteries, which have a separate origin from the tibial, and the metatarsal branch of the plantar 



aorta. One corresponds with the femoral ar- artery. 



1ery, and the other deserves the name of ischia- " The articular arteries go off next from the 



die artery. artery in the ham ; the two principal ones are 



"The femoral artery (23, fig- 170, 171) is a deep-seated. One proceeds under the vastus 



small trunk, which takes its origin from the side internus to the external part of the joint; the 



of the aorta, opposite to the notch in the bones of other is large, and situated upon the inside, 



the pelvis immediately under the last rib. This It forms two vessels : one is the true articular 



notch is formed into a round hole in the recent artery, and spreads upon the ligaments of the 



subject by a ligament which is extended from it joint; the other is distributed in the substance 



to the rib; and it is through this hole that the of the flexor of the heel, which is placed upon 



femoral artery makes its exit from the pelvis; just the inside and fore part of the leg, and comes 



before it passes out upon the thigh, it sends off a out upon the edge of this muscle to be lost in 



long branch (25), which runs backwards the the integuments. 



whole length of the margin of the pelvis, dis- " The posterior tibial artery (28, Jig. 171) 



pensing arteries to the abdominal muscles on one is extremely small ; it only supplies muscular 



side, and the obturator internus on the other, branches to the internal head of the gastrocne- 



This branch also appears to supply one to the mius, and some of the flexors of the toes ; it 



oviduct. The femoral artery, immediately after is lost on the inside of the heel in anastomoses 



leaving the pelvis, separates into two branches; with th peroneal artery, and other small 



one goes upwards and outwards, ramifying superficial branches. 



amongst the muscles in that situation ; the " The trunk of the artery of the leg now gels 



other turns downwards, and is distributed to upon the posterior surface of the tibia, and 



the flexors of the limb and round the joint, and sends off, through the deficiency left between 



sends an artery to the edge of the vastus inter- the tibia and fibula at the superior part, a 



nus, which can be traced as far as the knee, branch which is distributed to all the muscles 



The kidneys appear to derive some irregular upon the fore part of the leg. The artery then 



inconsiderable branches from the femoral artery creeps along the back of the bones for some 



while it is within the pelvis. way, and passing between them above, where 



"The ischiadic artery (26, jig. 166, 170) the fibula is anchylosed with the tibia, it re- 

 is the principal trunk of the lower extremities, appears on the anterior part of the leg in the 

 exceeding very much in size the femoral. When situation of the anterior tibial artery; at this 

 it is produced by the aorta, it appears to be the place it detaches some very small branches, 

 continuation of that trunk ; the remaining part which frequently divide and unite again, to 

 of the aorta becomes so much and so suddenly produce a most singular reticulation or plexus 

 diminished, and seems, as it were, to proceed as of vessels, which closely adheres to the trunk 

 a branch from the back part of the vessel. of the artery, and is continued with it as far as 



" The ischiadic artery, while in the pelvis, is the articulation of the tibia with the metatarsal 



concealed by the kidneys, in which situation it bone, where it disappears without seeming to 



gives a branch from its lower side, which di- answer any useful design. This plexus resem- 



vides into three others that are distributed to bles in appearance exactly the division of the 



the substance of the kidneys ; one of these on arteries of the extremities, which has been 



the left side is continued out of the kidney to described by Mr. Carlisle in the tardigrade 



be lost upon the oviduct. The artery leaves quadrupeds, but differs from it in this cir- 



the pelvis by the ischiadic foramen in company cumstance, that the trunk of the artery is pre- 



with the great nerve, while, within the foramen, served behind it, without suffering any "material 



it gives a branch obliquely downwards under diminution of its size. 



the biceps to the muscles lying in the pelvis ; " The anterior tibial artery furnishes no 



and as it passes over the adductor it sends off branch of any importance during the time it is 



another along the lower edge of that muscle, proceeding along the fore part of the leg. It 



which is chiefly lost in the semi-membranosus. passes under the strong ligament which binds 



It then detaches several small branches to the down the tendons of the anterior muscles of 



muscles on the outer and fore part of the the leg, and over the fore part of the joint on 



thigh, some of which anastomose round the the inside of the tendon of the tibialis anticus, 



joint with the branches of the femoral artery, at which places it distributes some branches 



Just as the ischiadic arrives in the ham, it which inosculate with the other arteries round 



furnishes a very large branch downwards, the joint ; it then pursues its course in the 



which divides into two ; one goes under the groove along the anterior surface of the meta- 



gastrocnemius, to which and the deep-seated tarsal bone, and covered by the tendon of the 



flexors its branches are distributed as far as the flexor digitorum. On coming near the foot it 



heel ; the other is analogous to the peroneal sends off an artery, which divides, behind the 



artery ; it goes to the outside of the leg, sup- joint of the internal toe, into two branches ; 



VOL. i. z 



