382 DISCOVERY REPORTS 



mentioned situated on the verumontanum. When the urinary passage is opened it is 

 seen that its longitudinally folded walls become smooth towards the °penmg into the 

 prostate. It narrows to the calibre of a bristle and 

 shows a single pronounced ridge projecting dorsally 

 into the lumen (Figs. 3 q, 6 c). This ridge is indepen- 

 dent of those which line the passage of the vesicular 

 part of the urinary duct. It rises up alone from the 

 smooth wall of the urinary passage and terminates in 

 a small tooth-like fibrous projection which fills the 

 urinary pore so that a bristle cannot be inserted into 

 the passage from the prostate. This tooth-like projec- 

 tion, the crista urethrae, appears to fulfil the function 

 of a valve, closing the entrance to the urinary duct and 

 possibly preventing contamination of the semen with 

 urine during coition. Daudt (1898, p. 294) described 

 three such cristae, two lateral and one dorsal, of 

 which the dorsal one was the largest. Only one was 

 found in the present work and Yves Delage (1885, 

 p. 121) found only one little transverse fold of mucosa. 



Immediately behind and slightly lateral to the urinary 



pore is a pair of minute crescentic openings (Fig. 6 d) 



upon the surface of the verumontanum. The openings 



are just wide enough to admit a bristle, and are the 



seminal pores through which the vasa deferentia open 



into the prostate. 



Cowper's glands are lacking in the Cetacea and there 



are no anal glands. 



Fig. 6. Horizontal section of the Pro- 

 stata and lower part of the urinary 

 canal in a 1-23 m. Fin whale foetus. 

 Ventral view, (x 2.) 



a. Urinary canal. 



b. Blind latero-dorsal terminations of 

 the prostatic portion of the urethra. 



c. Urinary pore and crista urethrae. 



d. Seminal pores. 



e. Dorsal ridge of the prostatic part 

 of urethra. 



/. Compressor prostatae muscle. 



The uterus masculinus 



No trace whatever of the uterus masculinus or sinus pocularis was found in either of 

 the foetuses examined. 



This is surprising in view of the fact that previous authors, with the exception of 

 Yves Delage (1885) and Meek (1918), have found traces of the uterus masculinus. 

 Delage carried out a large-scale dissection of an adult male Balaenoptera musculus 

 (now physalus), and described the verumontanum and openings of the vasa deferentia 

 in considerable detail. It seems unlikely that a sinus pocularis could have been 

 missed in material so large. This author emphatically denied its existence. Daudt 

 (1898, p. 295), however, in the same species, described a small sac which he took to 

 represent the uterus masculinus. " The dorsal part of the wall of the neck of the bladder, 

 towards which the folds are seen to converge, is itself somewhat swollen and imme- 

 diately behind this highest point a little pit sinks into the prostate wall... the little pit 

 corresponds to the vesicula prostatica " (uterus masculinus). Beauregard and Boulart 



