370 



W. HAROLD LEIGH-SHARPE 



little muscle or gland in the organ, may be explained by the fact 

 that the erigens nerve is also distributed to the prostate gland as 

 well as to the other pelvic viscera. The fibers going to the penis 

 are to be regarded as simply sensory in function, the real control 

 of the vasodilator effect being due to the secretion of a special 

 inhibitory substance by the prostate gland at the instigation of 

 the erigens nerve. Barrington has, however, shown that this is 

 not a true secretion, but is due to the pressing out of a secretion 



Fig. 8 A comparison of the typical cells of clasper glands under a high maj 

 nification. A, Raia; B, Lamna; C, Rhina. 



owing to the contraction of some of the muscles surrounding the 

 prostate gland. He has pointed out that a squeezing of the 

 gland takes place both when the pelvic and the hypogastric 

 nerves are stimulated, from which he concludes that the muscle 

 fibers round the gland are of two kinds, partly belonging to the 

 cloacal muscles, partly to the urodermal group. ^ 



The bearing which this investigation appears to have upon 

 this theory is that, of the fishes so far examined, those with 

 the best-developed clasper glands are also the ones with the most 



* Barrington, The variation in the mucin content of the bulbo-urethral glands. 

 Internat. Monatschr. f. Anat. u. Phys., Bd. 30, 1913. 



