FISHES CHAP. 
Kw 
tN 
N 
by several transverse anastomoses (Fig. 190). In the region of 
the heart each posterior 
cardinal joins the corre- 
sponding anterior cardinal 
to form a short but wide 
Cuvierian duct, which 
finally opens into the 
sinus venosus. 
A subintestinal vein 
is present in the embryo 
(e.g. Lepidosteus, Acipenser, 
and some Teleosts),’ but 
in the adult Teleostome 
its precaudal section is 
usually absorbed, or at 
all events ceases to be 
recognisable except, per- 
haps, as one of the minor 
he tributaries of the hepatic 
portal vein.” 
The hepatic portal vein 
is formed as in Elasmo- 
branchs, but in different 
Teleostomi it may also 
receive the veins from 
the pyloric caeca, from a 
portion of the air-bladder, 
Fic. 190.—Venous system of a Teleost (diagram- the gonads, and, as pre- 
matic). A, Auricle; ab.v, vein from the air- A 3 é 
bladder ; a@.c, anterior cardinal ; c.d, Cuvierian viously mentioned, a tri- 
duct ; c.p.c, transverse anastomoses between the butary from the caudal 
two posterior cardinals ; ¢c.v, caudal vein ; h.v, 
hepatic vein ; 7.j, inferior jugular ; %,kidney ; 7, VEIN. There are usually 
liver ; p.c, left posterior cardinal; p.v, hepatic two hepatic veins open- 
portal vein ; 7..c, right posterior cardinal ; 7.p.v,  , : E 
renal portal vein ; sc.v,, subclavian vein; sg.v, 10g into the sinus venosus, 
segmental vein ; sp.v, spermatic vein ; s.v, sinus and generally of equal 
nag size (Fig. 190). 
Most of the veins from the air-bladder join the hepatic portal 
Y V/ 
1 Balfour, Comparative Embryology, London, ii. 1881, pp. 66, 91, and 96. 
2 A subintestinal vein is also present in adult Holocephali (e.g. Callorhynchus 
antarcticus), T. Jeffery Parker, op. cit. p. 706. The persistence of this vein in 
adult Fishes is associated with the presence of a well-developed spiral valve. 
