328 MR. J. 8S. BUDGETT ON SOME POINTS IN 
will answer perfectly. for that in Polypterus, except that in my youngest specimen 
9 cm. in length I can find no trace of the nephrostomes opening into the ceelom 
described by him in “ larve” 12 cm. in length. It seems, then, that Calamoichthys, 
which is so much smaller in the adult than Po/ypterus, is in a more larval condition 
at 12 cm. length than is the Polypterus at 9 cm. 
It is possible that the nephrostomes never entirely close in Calamoichthys. However 
this may be, I have found in Polypterus no trace of nephrostomes opening into the 
ceelom. 
In my youngest specimens the uriniferous tubules were arranged in distinct 
metameric masses, the metamerism disappearing in older specimens. The glomeruli 
did not appear to be thus arranged, there being a very indefinite number of these 
structures to each metamere (PI. LL. figs. -10, 16, m.cps.). ‘The openings of the tubules 
into the ureter are far more numerous and irregular in the adult than in the young. 
V. The Ureters. 
The ureters lie along the whole length of the kidney between the outer ventral 
edge of the latter and the body-wall (Pl. L. figs. 2, 3; Pl. LI. figs. 10, 11, w.) (text- 
figs. 5, 6). They receive the kidney-ductules. The ureter on passing ventralwards 
from the hind end of the kidney becomes dilated, and, in the male, joining its fellow of 
the opposite side, forms a large urinary sinus (Pl. L. figs. 2, 5, 6; Pl. LI. fig. 12, w.s.), 
The urinary sinus still passing ventralwards to a position just dorsal to the rectum 
becomes constricted to a narrow neck and, just before opening to the exterior, receives 
on either lateral wall the opening of the genital duct, then opens to the exterior in a 
depression just posterior to the anus (PI. L. figs. 6, 7, 8, w.g.ap.). 
In the female the ureters do not become confluent until immediately before they 
open by a slit-like aperture just posterior to the anus. Otherwise they resemble 
entirely those of the male (text-fig. 6, p. 529). 
VI. General Considerations on the Structure and Growth of the 
Urinogenital Organs. 
It having been shown by Balfour and Parker and also by Semon that the testis of 
Lepidosteus, and perhaps also of Acipenser, was connected with the kidney-tubules, 
it was of extreme interest to see whether this were the case also in Polypterus, in many 
respects the most archaic of recent ‘Teleostomes. 
No such connections as a matter of fact exist. ‘The products of the testis pass out 
by a well-developed duct, which, running the same course as the ureter, opens into the 
lateral wall of the latter close to its termination (text-fig. 5). 
It is well known that the oviduct of the female Polypterus is short and is open 
anteriorly by a wide peritoneal funnel, the ova being shed through the external wall of 
the ovary into the body-cayity. This duct in the female runs a course similar to the 
