OF THE OEOAKS OF OENEEATION. 
57 
according to the distance of the kidneys from the anns, are 
of considerable size, longitudinally plaited on their inner 
surface, sometimes enlarged at their inferior extremity into 
a canal of varying size, originating from the superior end of 
the kidneys, and extending along the external border of 
these organs : they discharge the urine into the cloaca : 
their mouths are marked by two prominences, sometimes 
very distinctly salient, and prolonged into a cylindrical pro- 
tuberance. These same prominences perform the office of 
a penis, for it is by them that the sperm is discharged : 
the vasa deferentia open into the ureters. This being 
established, we must consider the two bodies which the 
male introduces into the cloaca of the female during copu- 
lation, and which afterwards are drawn within the tail, as 
simple holders^ by means of which these animals join or 
stimulate each other during that act. 
OF THE OEOAXS OF OEXEEATIOX. 
The dimensions of the bodies of which we have spoken 
in many species, the prickles with which they are often 
bristled throughout all their length, and, above all, the 
circumstance that they convey no liquid, are sufficient 
proofs to establish the assertion above stated, and to show 
the analogy between the arrangement of the true genera- 
tive organs in Birds and Ophidians. This false penis ^ 
which is found also among Saurians, is always a com- 
pound of two symmetrical bodies, exactly alike, which occupy 
the space at each side of the tail left by the transverse and 
inferior spinous processes. Each of these bodies is formed 
of a prolongation of the skin of the anus, which, descend- 
ing under the tail, forms a cylinder more or less long, and 
closed at every point. Exteriorly enveloped by tendinous 
membrane and by a distinct muscle, the inner surface of 
this cylinder is furnished with numerous appendages, some 
of which are soft, others hard ; some close set, little de- 
veloped, and not conspicuous ; while some are large, scat- 
tered about as prickles. This cylinder afterwards contracts, 
the prickles take the form of rugosities, their sides aug- 
ment in thickness, and their structure assumes an analogy 
