384 DISCOVERY REPORTS 



ducts, the median or vaginal part being absent. This must be a secondary condition 

 derived from that found in Mesoplodon, and it is conceivable that Meek may have 

 overlooked these distal vestiges. 



Thus, in the Cetacea, there is a great variety of conditions from complete absence 

 of any trace of the Mullerian system, through stages of extreme reduction, as in Kogia 

 breviceps, to the extreme development found in Mesoplodon. 



In other mammals the uterus masculinus presents an appearance similar to that of 

 Mesoplodon, most notably among the Rodents and Ungulates. The large prostatic 

 utricle of the rabbit is of somewhat doubtful homology, but in the beaver there is a 

 similar sac with two horns following the vasa deferentia. Among the Perissodactyle 

 Ungulates the horse, donkey and zebra have a long vagina masculina which is bifid at 

 its extremity. Among the Artiodactyles the goat and the reindeer have two long 

 Mullerian ducts continuing to the epididymis as in Mesoplodon. The deer has a much 

 reduced Mullerian system, the cavity of which is almost obliterated in the adult. 



The testes 



The testes retain their abdominal position throughout life and do not descend into a 

 scrotum. 



They are a pair of cylindrical bodies, slightly larger at their anterior extremities as 

 observed by Beauregard and Boulart, lying in the abdominal cavity immediately behind 

 the kidneys. On the left side of the body the testis lies against the hinder pole of the 

 kidney ; while on the right side, owing to the anterior position of the kidney on that side 

 of the body, the testis is separated by a slight gap from the posterior extremity of the 

 kidney. The testes lie with their axes converging slightly posteriorly. The anterior ends 

 of the testes are embraced by the heads of the epididymides, which form on each testis 

 a conical cap projecting forwards (Fig. i c) ; while the cauda epididymis lies along the 

 lateral face of the testis enclosed within the same serous envelope. The caput epididymis 

 is very intimately connected with the testis, and the vasa efferentia pass from the testis 

 to the epididymis across the junction between the two bodies. The cauda, however, is 

 connected with the testis along its length only by means of a narrow neck, so that a slit- 

 like bursa testis of considerable depth lies dorsally between the testis and epididymis. 

 The testis is attached to the lateral lining of the abdominal cavity by a mesentery, which 

 runs forwards lateral to the kidney up towards the diaphragm as a plica diaphragmatica 

 (Fig. i b). Behind the testes the mesenteries of the two sides form a common transverse 

 ligament exactly comparable with the ligamentum latum of the female (Fig. i g). This 

 ligament carries the vasa deferentia. Thus the attachments of the testes are exactly similar 

 to those of the ovary in the female. This is the primitive form of gonad attachment among 

 Mammalia — a posterior broad ligament and a plica diaphragmatica flanking the kidney 

 on each side. A stout genital cord (Fig. i i), the mesorchiagos of Eschricht, runs from 

 the posterior extremity of the testis itself, not of the cauda epididymis, to the posterior 

 lateral angle of the inguinal part of the abdominal cavity. The insertions of these fibrous 

 cords upon the abdominal wall are connected across the body cavity by a further 



