778 '/'///: M:I. 



largest, descends In tween tlio two priucii>ul digits, where it bifurcates; above, it gives a 

 brunch t tin- interim! digit. 



CAIINIVORA. In these animals, the lumbo-sacrul plexus is formed by tin la-t tour 

 lumbar nnd the fir.-t t\\<> sa.-ial. 



Tne crural nnd utilurntor mm 1 * which arise from tlic fourth, fifth, and sixth liiiiil.ur 

 nerves, ofter nothing piirticulnr in iheir ilisposition. 



Tlie iiil-riuil tni>hcnon* branch is as long as in the Pig; it pat-sou to the internal face 

 of the tarsus, lies alongside the fourth mctatarsal bone, and forms the internal d-r.-al 

 collateral of the fourth toe. 



The great sciatic may be de-scribed as having, as in Man, two terminal brunches 

 which separate a little above the posterior face of the femoro-tibial arlienhitioii. Tin; 

 external popliteal nerve passes to the surface of the external astrocnemius, en teis 

 between the common long tlexor of the toes and the long lateral }>eroiienl muscle, 

 where it bifurcates. The musculo-cutanetnu branch descends beneath the latter mut-cle 

 to the lower third of the leg, when it becomes superficial, and, accompanied by a v. in, 

 is lodged in the interspace between that muscle nnd the anterior tibial ; it pa-- 

 front of the tarsus, and reaches the upper part of the metatarsus, where it divides into 

 throe divisions. It must be mentioned that at, the ttbio tarsal articulation is thrown off 

 a very fine cord, which is directed outwards, and forms the external dorsal collateral 

 of the first toe. E'ich of its three terminal brunches courses along an iutermetn tarsal 

 space, and at th<- metatarso-phalangeal articulations separates into two filau 

 whence results the following distribution : the external branch forms the internal 

 dorsal collateral of the first toe and external of the second; the middle constitute-. 

 the inte:n;:l dorsal collaterals of the second toe and external of the third; last y. the 

 internal furnishes the internal dorsal collaterals of the third toe and external of the 

 fourth. The antn-inr ti!>!<tl mm.' accompanies the artery of that name, descends along 

 the external face of the tibia, and terminates in two branches at the tarsus. Of i 

 one is distributed to the tarsal articulations and the pedal nuihcle : the other, inteinal. 

 enters the interim tatarsal space, and at the corresponding metaturso-phalangcal joints 

 anastomoses with the internal blanch of the imisculo-cut.mcous nerve, and is l"8t in the 

 .-aim; parts. The internal ^topliteits foims the second terminal branch of the gre;it sciatic 

 nerve, and in the Day and Cat represents that portion of the latter which, in the Horse, 

 is situated behind the femoro-tibial articulation. It is continued by the poitcrim- lilinl 

 nerve, which terminates by the two plantar nerves. During its course, the external 

 popliteal furnishes articular and muscular filaments, as well as cutaneous twigs 

 .-ubsetjuently ; among the latter maybe mentioned the external saphenous, which arises 

 by two branches, and is expended behind the malleolus, at the outer side of the tarsus. 

 The plantar nerces are external ami internal; the latter lies at the inner border of the 

 t'-mli in of the superficial flexor muscles of the phalanges, and when it joins the middle 

 of the metatarsus, it detaches a fine filament that forms the internal plantar collateral 

 of the fourth toe; it then passes obliquely towards the first toe, at (lie deep face of the 

 above named tendon, and successively (iives off three filament one tor iach inter- 

 metatarsal f-paeo. These filaments anastomose wilh the terminal brandies of the 

 external plantar, at t!;e metatar.so-phalangeal articulations; the first two filaments 

 supply the large cushion of the paw. 



The >-.rf, ,-iial i>l<tntar nervr. passes between the two flexor tendons i.f the toes, whue 

 it gives a filament that constitutes tlic external plantar collateral of the first toe. It is 

 afterwards placed outside the deep tlexor, then enters beneath the short flexor an I 

 divides into several branches, muscular and digital. Each of the latter, three in 

 number, JLIS-CS into a oomffpandioe i iterosseous space and bifurcates at the im t ttarso- 

 |ihiilangeid articulations, receiving filaments from the internal plantar, and forming the 

 following plantar collati rals : the internal of the first toe, int< ninl and external of the 

 second, internal and external of the third, and external of the fourth digit. 



COJ1FAIIISON OF THE LUM BO-SAC UAL 1'LEXrs OF MAN WITH THAT OK ANIMUS. 



It is usual, in human an:itiny, to describe a lumbar and a sacral plo\n-. 



The lumbar plexus is constituted by the anastomoses of the anterior branches of the 

 five lumbar nerves; 1 these are united by fine filament-, \\hi.-li arc not intricately 

 associated. The divisions of this plexus are distinguished as ri,ll,if, ml and li-rminnl 

 branches. The first, d' stined to the upper part of the limb and the skin covering the 



(' Wilwm *ays the four upper him' ar nerves and the la-t dorsal; Heath gives the 

 Mime constitution.) 



