980 



TESTICLE (NORMAL ANATOMY). 



epididymis are entirely made up of the con- didymis or vas deferens. It is more com- 

 volutions of the single canal in which the nionly attached at the angle formed by the 



Fig. 634. 



Fig. 635, 



An efferent vessel and a portion of the head of the 

 epididymis magnified, to show the progressive dimi- 

 nution of the canal of the cone, and the calibre of 

 this vessel, in comparison with that of the canal of 

 the epididymis. 

 c, vas deferens ; d, inflected portion of the duct ; 



e e, head of the epididymis. (After Lauth. ) 



vasa efferentia terminate, closely connected 

 by areolar tissue. Monro described this canal 

 as gradually increasing in size from the head 

 to the tail, and he estimated its calibre about 

 its middle at V f an mcn - Lauth states 

 that its size is subject to great irregularities in 

 different parts and in different subjects. This 

 anatomist has particularly described the con- 

 volutions of this duct, and has shown that they 

 are regularly arranged in four series, which 

 successively increase in size ; the first being 

 the smallest, and the fourth the largest. The 

 arrangement will be understood by reference 

 to the subjoined figure. Monro estimated the 

 length of the canal at thirty feet eleven inches. 

 Lauth found its mean length to be nineteen 

 feet four inches eight lines. The parietes of 

 the canal are strong, and bear considerable 

 resistance. The canal of the epididymis ter- 

 minates in the excretory duct of the testicle, 

 the vas deferens, and is usually contracted at 

 the part where the two join, which accounts 

 for the mercury when forced into the vas de- 

 ferens being often arrested at this point. It 

 was calculated by Monro that the semen, be- 

 fore arriving at the vas deferens traverses a 

 tube forty-two feet in length. Lauth, how- 

 ever, makes the whole distance but little more 

 than twenty-two feet. 



Vasculum aberrans. This name was given 

 by Haller to a blind duct or ccecal appendage 

 often found connected either to the epi- 



Canal of the epididymis partly unravelled, to show the 

 four series of inflections which the duct undergoes 

 in the several divisions of the epididymis. 

 o, o, first series of inflections ; p, p, second series ; 



q, q, third series ; r, r, fourth series. (After Lauth). 



termination of the former in the latter. (Figs. 

 632., and 633, A.) It forms a convoluted 

 duct as large as the canal of the epididymis, 

 which is contracted at its insertion, and ter- 

 minates in a blind and often dilated extremity. 

 Sometimes after being dilated for a certain 

 distance it diminishes, and becoming very 

 minute, is lost in the areolar tissue of the 

 cord. It usually passes up the cord for about 

 two or three inches, but has been found to 

 extend as far up as the brim of the pelvis. 

 The length of this appendage when unravelled 

 varies from one to twelve or fourteen inches. 

 The vasculum aberrans is not constantly pre- 

 sent ; indeed, Monro found it only four times 

 in sixteen ; but I believe, with Lauth, that it 

 exists more frequently. Occasionally there is 

 more than one, and as many as three have 

 been found both by Lauth and Sir A. Cooper. 

 Hunter regarded these ducts as supernumerary 

 vasa deferentia, of a nature similar to the 

 double ureters.* Miiller states that their 

 office is evidently the secretion of a fluid 

 which .they pour into the epididymis. f We 

 have no evidence, however, that the duct 

 serves any particular office. 



Vas deferens, the excretory duct of the 

 testicle, commences from the tail of the epidi- 

 dymis, and terminates in one of the ejacu- 

 latory canals behind the bladder, being in 

 length from fifteen to sixteen inches. Arising 



* Works by Palmer, vol. iv. p. 24. 



t Physiology, trans, by Baly, vol. i. p. 45 



