REGIONAL ANATOMY 27 
(a) The Solar Plexus.—The veins of this plexus dis- 
charge themselves in two directions : (1) By a central canal 
or canals running along the bottom of the lateral lacune 
of the plantar cushion to gain the deep layer of the 
coronary plexus. (2) By the Circumflex or Peripheral Vein 
of the Toe, a canal formed by ramifications from the solar 
and the podophyllous plexuses, and following the direction 
of the artery of the same name. The circumflex vein 
terminates by forwarding branches to concur in the forma- 
tion of the superficial coronary plexus. 
(6) The Podophyllous or Laminal Plexus.—The podo- 
phyllous veins anastomose below with the circumflex vein 
of the solar plexus, and above with the veins of the 
coronary plexus. 
(c) The Coronary Plexus.—This proceeds from the podo- 
phyllous, the intra-osseous, and the solar networks, and 
consists of a central and two lateral parts. 
The central portion lies between the lateral cartilages 
and immediately under the coronary cushion. The lateral 
portions are rathifications on both surfaces of the lateral 
cartilages. The ramifications on the lateral cartilages 
may be again distinguished as superficial and deep. The 
superficial layer is distributed over the external face of the 
cartilage, forming thereon a dense network, and finally 
converges towards the superior limit of the plexus to form 
ten or twelve principal branches, which again unite to 
form two large vessels. These vessels, by their final fusion 
at the lower end of the first phalanx, constitute the digital 
vein. The deep layer is formed, as before described, by 
ascending branches from the posterior parts of the podo- 
phyllous and solar plexuses, and by branches from the 
intra-osseous system of the pedal bone. The veins of this 
deep layer finally drain into the two vessels proceeding 
from the superficial layer, which go to the formation of the 
digital vein. 
Tue Dierran Verns.— These arise from the network 
formed on the surfaces of the lateral cartilages, and ascend 
in front of the digital arteries to unite above the fetlock, 
