616 THE VEINS. 



venous system and those coming from the tendons and ligaments, forming a 

 fasciculus of five or six thick converging veins which unite in two large 

 ascending branches. These anastomose with each other before their de- 

 finitive junction with the two peripheral branches resulting from the super- 

 ficial cartilaginous plexus, with which they concur in constituting the 

 digital vein." 



h. Internal, or Intro-osseous Venous Apparatus. 



" Girard, the younger, and Eigot have denied that the plantar artery had, 

 in the interior of the phalanx, a satellite venous system. These two able 

 anatomists committed an error. 



" The disposition of the venous apparatus in the interior of the phalanx 

 is absolutely identical with that of the arterial. 



" The satellite radicular venules of the terminal arteries converge, by 

 forming successive anastomoses, towards the semilunar sinus, into which 

 they enter by the anterior interosseous canals, ascending and descending, and 

 by which the emergent arteries from the semilunar anastomosis pass out- 

 wards. There they join into a semicircular canal, the satellite of that 

 anastomosis, which is continued backwards by two eiferent veins that follow 

 the posterior canals of the semilunar sinus, emerge by the plantar foramina, 

 pass into the fissure of the same name, ascend within the basilar process, 

 lie at the internal face of the cartilaginous plate, in one of the infractuosities 

 with which it is sculptured, and concur in the formation of the deep layer 

 of the cartilaginous plexus. 



" Beside these veins converging towards the cartilaginous plexus, there is 

 a small number of divergent ones which follow the track of the arteries, and 

 pass into tho podophyllous plexus through the anterior porosities of the 

 phalanx, 



" The dissection of specimens injected by the veins puts this arrangement 

 of the venous apparatus in the interior of the os pedis beyond a doubt. 



" But is this internal venous system limited to the group of vessels which 

 are satellites of the arteries, or is it not rather extended over a vaster 

 surface, and may not all the areolse of the spongy tissue of the bone be 

 considered as a dependency of it ? 



" This way of viewing it would seem to be supported by the result of 

 certain injections, in which the material introduced by the neighbourmg 

 veins has filled all the internal spongiolee of the bony tissue ; though this 

 was probably due to an accident in the operation, and it is presumable that 

 the direct passage of the venous injection into the areola of the spongy 

 tissue arose from a rupture in the vascular walls. If the tissue of the 

 phalanx formed a kind of diverticulum for the venous system, as the opinion 

 just given would admit, operations performed on this part during life, when 

 the texture of the bone is deeply involved, ought to be foUowed by he- 

 morrhage from the open orifices of these aerolse— a circumstance which 

 does not take place. 



" It does not appear, therefore, that there is in the structure of the third 

 phalanx any departure from the general plan on which bones are constructed, 

 and we thmk that its internal veinous system is limited to the vessels, very 

 numerous as they are, which accompany the arterial divisions " 



