THE SPERMATIC DUCTS. 235 



THE APPENDAGES OF THE TESTICLE. 



Under this heading are included several vestigial organs that remain for 

 a variable period, some throughout life, as more or less conspicuous bodies 

 attached to the testis or the epididymis. They claim attention not only on 

 account of their morphological relations, but also because they may become 

 the seat of pathological changes. The most important are : the appendix 

 testis, the appendix epididymidis , the paradidymis and the duduli aberr antes. 



The appendix testis, also called the unstalked or sessile hydatid, is a 

 small but fairly constant body, 5-10 mm. in length and less than half as broad, 

 fixed to the upper pole of the testis. It consists of a vascular connective tissue 

 stroma in which lies a minute canal of variable size and extent, lined with 

 columnar epithelium. The appendage represents the atrophic upper end of 

 the Miillerian duct, one of a pair of foetal tubes that in the female embryo 

 give rise to the oviducts, the uterus and the vagina. 



The appendix epididymidis, or stalked hydatid, is a small pyriform 

 sac, from 3-4 mm. in length, containing a clear fluid and lined with cuboidal 

 epithelium. It is variable in form, size and number, two or more sometimes 

 being present, and is probably derived from the tubules of the fcetal Wolffian 

 body. 



The paradidymis, or organ of Giraldes, consists of an irregular group 

 of blind tubules, from 5-6 mm. in length, that lies within the lower end of 

 the spermatic cord, above but close to the head of the epididymis. The 

 tubules are lined with cuboidal or columnar ciliated epithelium and are 

 derivatives of the Wolffian tubules. 



The ductuli aberrantes include tubular appendages, usually an upper 

 and a lower, that extend for an uncertain distance within the epididymis 

 among the convolutions of its duct. The tubules are lined with ciliated 

 columnar or cuboidal epithelial cells and are regarded as originating from 

 the atrophic tubules of the Wolffian body. 



THE SPERMATIC DUCTS. 



The spermatic duct, in the more usual and restricted sense, is one of a 

 pair of tortuous canals that connect the epididymis with the urethra and thus 

 provide channels for the escape of the secretion of the sexual glands. Each 

 duct is conventionally described as composed of the vas deferens and its 

 ampulla and the ejaculatory duct ; at the upper end of the latter the sper- 

 matic duct is connected with the seminal vesicle, a saccular organ derived as 

 an outgrowth from the main canal. 



The Vas Deferens. This tube extends from the epididymis to the 

 ejaculatory duct and, when straightened out, measures some 45 cm. (18 in.), 

 thus contributing almost the entire length of the spermatic duct. Its 

 diameter is from 2-3 mm. Within the spermatic cord (pars funicularis) the 

 vas occupies a position behind the other constituents of the cord and may 

 be recognized by the hard cord-like feel imparted by its thick fibro-muscular 

 wall. The latter (11.5 mm - thick) encloses a narrow lumen and consists 

 of three coats the mucous, muscular and fibrous. The mucous coat is 

 clothed with epithelium which for a considerable distance resembles that of 

 the canal of the epididymis, being made up of a superficial layer of columnar 

 and a deep one of small rounded cells. Throughout the upper part of the 

 duct, however, the cells are lower, without cilia, and approach a simple 



