414 
MESSRS. E. M. BALFOUR AND W. N. PARKER ON THE 
the case with piscine testes, divided into a series of lobes (10-12), and were suspended 
by a delicate mesentery (mesorchium) from the dorsal wall of the abdomen on each side 
of the dorsal aorta. Hyrtl (No. 11) states that air or quicksilver injected between 
the limbs of the mesentery, passed into a vas deferens homologous with the oviduct 
which joins the ureter. We have been unable to find such a vas deferens; but we 
have found in the mesorchium a number of tubes of a yellow colour, the colour being 
due to a granular substance quite unlike coagulated blood, but which appeared to us 
from microscopic examination to be the remains of spermatozoa.* These tubes to the 
number of 40-50 constitute, we believe, the vasa efferentia. Along the line of suspen¬ 
sion of the testis on its inner border these tubes unite to form an elaborate network 
of tubes placed on the inner face of the testis—an arrangement very similar to that 
often found in Elasmobranchii (vide F. M. Balfour, £ Monograph on the Develop¬ 
ment of Elasmobranch Fishes,’ plate 19, figs. 4 and 8). 
We have figured this network on the posterior lobe of the testis (fig. 58 B), and 
have represented a section through it (fig. 59 A, n.v.e.), and through one of the vasa 
efferentia (v.e.) in the mesorchium. Such a section conclusively demonstrates the real 
nature of these passages : they are filled with sperm like that in the body of the 
testis, and are, as may be seen from the section figured, continuous with the seminal 
tubes of the testis itself. 
At the attached base of the mesorchium the vasa efferentia unite into a longitudinal 
canal, placed on the inner side of the kidney duct (Plate 26, fig. 58 A, lx., also shown 
in section in Plate 26, fig. 59 B, lx.). From this canal tubules pass off which are 
continuous with the tubuli uriniferi, as may be seen from fig. 59 B, but the exact 
course of these tubuli through the kidney could not be made out in the preparations 
we were able to make of the badly conserved kidney. Hyrtl describes the arrange¬ 
ment of the vascular trunks in the mesorchium in the following way (No. 11, p. 6): 
“ The mesorchium contains vascular trunks, viz., veins, which through their numerous 
anastomoses form a plexus at the hilus of the testis, whose efferent trunks, 13 in 
number, again unite into a plexus on the vertebral column, which is continuous with 
the cardinal veins.” The arrangement (though not the number) of Hyrtl’s vessels is 
very similar to that of our vasa efferentia, and we cannot help thinking that a con¬ 
fusion of the two may have taken place; which, in badly conserved specimens, not 
injected with semen, would be very easy. 
We have, as already stated, been unable to find in our dissections any trace of a 
duct homologous with the oviduct of the female, and our sections through the kidney 
and its ducts equally fail to bring to light such a duct. The kidney ducts are about 
19 centims. in length, measured from the genital aperture to their front end. These 
ducts are generally similar to those in the female ; they unite about 2 centims. from 
* The females we examined, which were no doabt procured at- the same time as the male, had their 
oviducts fdled with ova: and it is therefore not surprising that the vasa efferentia should be naturally 
injected with sperm. 
