CHAP. XXXVII.] 



SEMINAL TUBULES. 



545 





hair follicles, as is usual in other situations in which they are found. 

 The peculiar secretion known as the smegma preputii, is not due to 

 these glands alone; but is rather to be regarded as an accumulation 

 of the moist epithelium of the glans, which is, of course, mixed 

 with the odoriferous sebaceous material. In the beaver, the epi- 

 thelial secretion is so abundant, as to accumulate in large pre- 

 putial pouches, the true nature of which was demonstrated by 

 E. H. Weber. The secretion constitutes the substance known as 

 castor. 



Vesicula Prostatica. Between the openings of the ejaculatory 

 ducts in the middle line of the urethra, and in the substance of the 

 caput gallinaginis, is a small cavity, lined with columnar epithelium, 

 the prostatic vesicle, or uterus masculinus, as it has been termed by 

 Weber, from its supposed homology with the female organ. It 

 has since been described under the name of Weberian organ, from 

 its discoverer. 



Seminal Tubules. The highly tortuous seminal tubes, of which 

 the true secreting portion of the testicle is composed, consist 

 of a fibrous coat, internal to which we find a basement mem- 

 brane surmounted by epithelium. Now the characters of this 

 epithelium, and the nature of the contents of the tube, will be 

 found to exhibit dif- 

 ferent appearances, ac- 

 cording to the age of 

 the individual; and in 

 the lower animals, ac- 

 cording to the period 

 of the year. Sperma- 

 tozoa, which are the 

 fertilizing agents, are 

 not found before pu- 

 berty in man, and 

 among animals are 

 only developed at cer- 

 tain periods. These 

 bodies appear to be 

 formed by certain al- 

 terations taking place 



. --IT p .-, Portion of seminal tubules of man, with enclosed cells. Magnified 



in the Character OI the 220 diameters, a. Wall of the tube. b. Nuclei of fibrous coat. c. 



.,, ,. ,. . ,, Basement membrane. The latter figure represents the action of 



epithelium lining the acetic acid. d. Cells removed from the tubule. 



tubes, for this latter is most distinct when spermatozoa are not 

 being formed ; but when the function of the gland is very actively 



Fig. 260. 



