280 



HISTOLOGY. 



closed in the connective tissue wall of the duct. Some of these append- 

 ages show the same structure as the seminal vesicles and therefore might 

 be described as accessory seminal vesicles; others are simply convolu- 

 tions of alveolo-tubular glands, which may be compared with prostate 

 glands. The mucous membrane of the ductus ejaculatorii is like that of 

 the seminal vesicles, except that its folds are not so complicated. Muscle 

 fibers occur only around the appendages. The wall of the duct itself con- 

 sists of an inner dense layer of connective tissue with circular strands, and 

 an outer loose layer (adventitia). 



APPENDICES AND PARADIDYMIS. 



The appendix testis [hydatid of Morgagni, sessile hydatid] is a small vas- 

 cular nodule of connective tissue covered with peritonaeum of the tunica vaginalis, 

 except at its stalk of attachment. It contains one or more fragments of a small 

 canal, closed at both ends, occasionally having blind out- 

 pocketings. The canals are lined with simple columnar 

 epithelium sometimes ciliated. The peritonaeal cells 

 over a portion of its surface are columnar and have 

 been interpreted as the evaginated end of the Miiller- 

 ian duct. 



The appendix epididymidis [stalked hydatid] is not 

 always present. Among 105 cases examined by Toldt 

 it was found 29 times. It consists of loose vascular 

 connective tissue covered by the vaginalis, and contains 

 a dilated canal lined with columnar epithelium some- 

 times ciliated. The canal has no connection with the 

 tubules of the epididymis. Its embryonic history is ob- 

 scure. 



Cysts found in the vicinity of the epididymis may 

 arise from pockets of the tunica vaginalis. 



The paradidymis is found "frequently but not 

 always in older embryos and children, as an elongated, 

 whitish structure on the ventral side of the spermatic- 

 cord. It is sometimes just above the head of the epi- 

 didymis, sometimes higher, but always in front of the venous plexus. A second, 

 lower part of the paradidymis is found in late childhood, but not as a rule in 

 the adult. It is a macroscopic coiled canal with outpocketings, found behind 

 the head of the epididymis and in front of the pampiniform plexus." (Eberth.) 

 The upper portion represents the anterior part of the Wolffian body, which is 

 not involved in the formation of the testis. It contains pigment derived from the 

 degenerated Wolffian glomeruli. Cilia, which occur at birth, later disappear. 

 The lower section may connect with the tubules of epididymis and contain 

 spermatozoa, or it may be completely detached. Its tubules are made of col- 

 umnar epithelium, simple or stratified, sometimes ciliated, and they show 

 elevations suggesting those of the efferent ducts. Often they become cystic. 



PROSTATE. 



The prostate consists of from 30 to 50 branched alveolo-tubular 

 serous glands, which grow out from the prostatic urethra, and surround 



FIG. 319. FRONT VIEW OF 

 A TESTIS, natural 

 size. (After Eberth.) 



a. e., Appendix epididy- 

 midis; a. t, appendix 

 testis; c. e., caput epi- 

 didymidis; t, testis; 

 t. v., tunica vaginalis. 



