CHAP. XXXVII.] 



TESTICLE. 



539 



are arranged in conical lobes, or parcels, each consisting of two or 

 more tubes, which are covered with a lay er of condensed areolar tissue, 

 continuous with the corpus Highmori. These divisions are, however, 

 not complete ; for the tubes of one parcel communicate with those 

 of the adjoining ones. The highly convoluted seminal tubes com- 

 mence in blind extremities or in loops ; and, after dividing fre- 

 quently, and forming anastomoses, they become less tortuous as 



Fig. 256. 



257 - 



o. Origin in blind extremities and branching of seminal tubules human subject, b. One of the 

 blind extremities more highly magnified. 



they approach the mediastinum testis, where two or more unite to 

 form a short straight duct, the vas rectum; 

 these vasa recta again unite, so as to form 

 a sort of net-work, the rete testis, which 

 occupies the mediastinum testis or corpus 

 Highmori. From the rete testis pass the 

 vasa efferentia, which are usually about 

 twelve or sixteen in number, and are 

 much convoluted; and, by being packed 

 together, form part of the epididymis. 

 They open into a single and highly tor- 

 tuous duct, the vas deferens, which is 

 usually about sixteen inches in length, and 

 forms a very hard, round efferent duct, 

 readily distinguished, by the feel, from 



. i i i j.1 Transverse section of the vas defe- 



the Other Structures WhlCh. COmpOSe the rens a segment only is represented 



spermatic cord. The vas deferens is i] 



lined with a single layer of tesselated 



epithelium, and there is a layer of very 



lax areolar tissue beneath the mucous 



membrane, which would permit of great ^ Bet?' '' ' 



N N 2 



f the tube connected by a thick 

 layer of lax submucous areolar tissue 

 (b) to a thin longitudinal layer of un- 

 striped muscle (c.)d. Layer of circular 

 e. External 



