152 ON THE ORGANS OF GENERATION, &C. 
either of the ureters, the urinary bladder may be readily 
distended, and will remain so, though no compression of 
the urethra be employed. 
I did not satisfactorily make out the supra-renal glands, 
but I am willing to ascribe this apparent exception to a 
very general law, to the state of the organs, which did not 
permit me to distinguish them from the kidneys. 
The dissection of the organs of generation in the male 
Ornithorynchus was performed with a care proportioned 
to the usual intricacy of the parts, and to my knowledge 
of the very extraordinary contradictions existing in the 
writings of authors of the highest merit. The errors which 
anatomists had committed in their descriptions of the or- 
gans of defence, the poison-gland and spur, I am still in- 
clined to consider as purely an omission on their part ; for 
such was the distribution of the gland and duct, as exhi- 
bited in drawings to the Society, so easy its display, that 
the merest student in anatomy could, with sufficient pa- 
tience, have made out the structure of the whole; but 
every anatomist knows, that the organs of generation are, 
generally speaking, the most complex of the frame, and re- 
quire, in order to be unravelled, the most delicate dissec- 
tion. The result of the inquiry is as follows. 
The preparatory male organs, that is, the testicles, are 
placed in the abdomen near the kidneys, and they seemed 
to me to be constantly fixed there. The epididymis was 
proportionally large, but I could perceive nothing very 
remarkable in the vasa deferentia^ which proceeded direct- 
ly, without any dilatation, but rather a slight contraction, 
to terminate in the urethra, close to the entrance of the 
urinary bladder, into the same canal. The small longitu- 
dinal holes, by which they open into the urethra, are di, 
rected upwards, so that on introducing the tube of an 
Anel'^s syringe into the vas deferens near the epididymis, 
