TEE EXTERNAL ILIAC ARTERIES 641 



Anterior tibial artery. — After passing down along the leg on its antero-external face, as in 

 Solipede, this vessel arrives on the hock, where it takes the narae o{ pedal artery, and funiishis 

 the per/oratittg-pedal artery ; it is continued by tlie metatarso-pedal or collateral artery of tiie 

 cannon. 



a. The perforating pedal artery does not difTer from that of the Horse. 



b. Tlie metatarifo-pedal, or collateral of the cannon, descends, flanked by two satellite veins, 

 in the channel on the anterior face of the metatarsal bone, giving off towanls the inferior 

 extremity of that channel, the perforating branch already spoken of, and is continued into the 

 digital region as the common digital artery. 



The perforating Irranch of the collateral of the cannon passes into the foramen pierced from 

 before to behind, across the inferior extremity of tiie metatarsal bone, arriving beneath the 

 suspensory ligament, and then divider into several ascending and descending branches. The 

 first join the deep and superficial posterior metatarsal arteries furnished by the plantar and 

 pedal perforating arteries. Among tlie secoud, we notice three digital arteries, facsimiles in 

 miniature of those which will be described in the anterior limb : two lateral, descending on the 

 eccentric side of tlie phalanges ; a median, turning within the flexor tendons to phu-e itself 

 behind them on the middle line of the digital region, and prolonged into the iuterdigital space, 

 where it anastomoses with a branch of the principal artery of the digits. 



The latter artery — the common digital — descends into the space between the digits, after 

 passing btneath the capsular ligament of tlie nietatarso-phalangenl articulations, in the notcli 

 between the two articular surfaces of the nietatjiisal bone, and terminates above the inferior 

 extremity of the first phalanx by two ungual arteries, the description of which will be reserved 

 until describing the arteries of the anterior limb. In the number of collateral branches 

 emanating from this vessel, there may be particularly remarked a large offshoot which arises 

 a little before the separation of the two ungual arteries, and is directed from before to behind, 

 dividing at the posterior part of the iuterdigital space into several divisions, the principal of 

 which are : 1. Two transverse branches passing between' the flexor tendons and the phalanges, 

 to be joined to the lateral digital arteries. 2. A single ascending branch, joining with the 

 posterior median digital artery. 3. A descending branch, also single, dividing into two por- 

 tions which reach the heels, to be distributed to the plantar cushion and the villous tissue. 

 These branches represent the arteries of the plantar cushion in the Horse, ami will be noticed 

 more iu detail in the description of the arteries of the anterior limb, where in principle they are 

 found to be exactly like these. 



2. External Iliac Arteries of the Pig. 



The distribution of these vessels in the Pig is remarkably like that we have described as 

 existing in Ruminants, even in the terminal portions of the limbs, notwithstanding the com- 

 plete development of the two lateral digits. It may l)e noted, however, that the posterior tilial 

 artery is somewhat slender, and that it is singularly increased by its anastomosis with the 

 saphena artery, the dimensions of which are relatively considerable.' 



3. External Iliac Arteries of Carnivora. 



The external iliac is divided in the Carnivora, as in the other animals, into three sections : 

 the proprr iliac artery, the femoral artery, and the popliteal artery, terminated by the tibial 

 branches. 



Proper iliac artery. — This vessel does not give rise to any branch, as the circumflex iliac 

 comes directly from the posterior aorta. 



Femoral artery. — As in the Horse, this gives oflF: 1. Several muscular innominate branches. 

 2. Two great muscular arteries, the posterior of which furnishes the prepubic artery. 3. A 

 saphenal branch. 



In the Bitch, the external pudic artery, emanating from the prepubic division, presents 

 eome peculiarities in its distribution. It gives oti' a long branch which is placed in the texture 

 of the mammae, and pa.'jses forward to meet and unite with the mammary branch furnished by 

 the internal thoracic artery ; it then runs between the two thighs in a flexuous manner, and 

 reaches the lipe of the vulva, where it ends in numerous ramuscules that anastomose with the 

 vulvar divisions of the internal pudic artery. 



The saphena artery is as remarkable for its large volume as for its destination. It descends 



' In small Ruminants, the posterior tibial artery, properly speaking, is equally rudimentary ; 

 the saphena artery constitutes the principal vessel. From a note which we made a long time 

 ago, it appears the first vessel is altogether absent sometimes, and that the plantar divisions 

 come exclusively from the saphena, as in the Carnivora. 



