976 



favour of that of excess or irregular distri- 

 bution of developemental power, for preferring 

 to regard them as examples rather of single- 

 ness tending to duplicity than of duplicity 

 tending to singleness, are briefly these : that 

 it is probable that the whole class of monsters 

 by excess owe their origin to different de- 

 grees of one common fault, and consequently 

 that the explanation of their origin ought to 

 be the same for all ; that no kind of fusion 

 can account for the production of super- 

 numerary individual organs, the rest of the 

 body being single ; but that it is not impos- 

 sible that excess of power in the ovum, which 

 all admit can alone explain the lower degrees 

 of duplicity, may, in proportionally higher 

 degrees, perhaps by the formation of two 

 primitive grooves, produce the more complete 

 double monsters, or even two such separate 

 individuals as are sometimes found within a 

 single amnion. 



BIBLIOGRAPHY. On account of the length of 

 this Article, and the great number of books upon the 

 subject, I shall omit the Bibliography, and refer to the 

 foot-notes as Avell as to the manuals of Meckel, Ro- 

 kitansky, Geoffrey St. Hilaire, von Amnion, and my 

 own, in which the bibliography is duly noticed. 



(W. Vrolilc.) 



TESTICLE. (HUMAN ANATOMY). Gr. 



opxts ; Latin, Testis Testiculus ; French, 

 Testicule ; German, Hode ; Italian, Testicolo. 



The testicle is the gland by which the 

 semen or spermatic fluid is secreted. Two in 

 number, and contained within the scrotum, 

 these organs are suspended at a variable and 

 unequal distance from the abdominal rings, 

 one testicle, generally the left, hanging a little 

 lower than the other. This arrangement pre- 

 vents collision between these organs when the 

 thighs are suddenly approximated ; one tes- 

 ticle slipping above the other, and thus elud- 

 ing violence. In cases of transposition of the 

 viscera and blood-vessels, it has been observed 

 that the right testicle hangs lower than the 

 left. 



The shape of the testicle of an adult is that 

 of an oval with flattened sides. The organ 

 has two extremities, an antero-superior, and 

 a postero-inferior ; and two lateral surfaces. 

 Its position in relation to the body is rather 

 oblique, its long axis or antero-posterior di- 

 ameter passing from above downwards and a 

 little inwards. Its edges and sides are convex. 

 Its upper extremity is rounded and capped by 

 the epididymis, which rises above the body 

 of the gland like the crest on a helmet. Ac- 

 cording to Cruveilhier the testicle measures 

 two inches in length, one inch in breadth, and 

 eight lines in thickness. Sir Astley Cooper 

 makes its long diameter two inches ; its trans- 

 verse, an inch and a half; and its lateral, one 

 inch and one eighth. I have found the mean 

 dimensions of the testicle to be one inch and 

 three quarters in length, one inch and a quarter 

 across or in breadth, and one inch in thirk- 

 ness or from side to side. Meckel states its 

 average weight to be four drachms, and Sir 

 A. Cooper about an ounce. I have found the 



TESTICLE (NORMAL ANATOMY). 



mean of these two estimates, viz. six drachms, 

 to be the ordinary weight of the sound testicle 

 of a healthy adult. * There are few organs 

 subject to greater variations in size and weight 

 than the testicle, even in men of the same age^' 

 and constitution % The testicles also o/'tlie 

 same individual rarely agree, the volume <md 

 weight of the left being, in general,- greater 

 than those of the right. I weighed the tes- 

 ticles of six men, two of whom were killed by 

 violence, and found the left gland heavier than 

 the right in five; in neither of these instances, 

 however, was the difference more than a 

 drachm. The organ feels tense, compact, and 

 slightly elastic. Its degree of consistence 

 depends more on the tension of the tunica 

 albuginea than on the proper substance of the 

 gland. It is a good deal influenced by the 

 quantity of seminal fluid contained in the 

 tubular structure, and its state of activity or 

 rest ; the gland being tense and tumid when 

 the organ is exercised and the tubuli are dis- 

 tended, and soft and flaccid, when they are 

 empty and the gland inactive. The parts 

 composing the testicle may be described under 

 four heads : 1. The protective parts or 

 tunics ; 2. The proper glandular or secreting 

 structure ; 3. The excretory parts ; 4. The 

 vessels and nerves. 



1. The Protective Parts or Tunics. The 

 Tunica Vaginalis. This is a delicate serous 

 membrane in the form of a shut sac, which 

 consists of two portions ; an outer one, the 

 parietal, which is free and loose ; and an 

 inner, reflected, visceral or testicular portion, 

 which closely invests the gland. The two 

 portions are connected and continuous with 

 each other. The outer one loosely invests 

 the whole of the testicle except its posterior 

 edge and inferior extremity, parts where the 

 membrane becomes attached to the gland. 

 It is connected with the testicle at about five 

 lines from the lower extremity, and the junc- 

 tion of the two portions is marked by a white 

 and rather irregular line. The uncovered por- 

 tion of the organ corresponds to the original 

 attachment of the gubernaculum. On the 

 inner side of the gland the membrane, after 

 investing the lower part of the cord to a 

 greater or less extent, is reflected to the epi- 

 didymis just below its head, and to the pos- 

 terior edge of the body of the testis, being 

 there separated from the epididymis by the 

 vas deferens and blood-vessels of the gland. 

 On the outer side the membrane entirely 

 covers and closely invests the epididymis, 

 and forms a cul-de-sac, which isolates its mid- 

 dle from the posterior border of the testicle, 

 and in cases of hydrocele is often distended 

 into a pouch. At the bottom of this sac the 

 tunica vaginalis on the two sides comes into 

 close contact, and sometimes there is a com- 

 munication at this spot bet\veen the two. The 

 smooth and polished surface of the shut sac 

 thus formed by the tunica vaginalis is lubri- 



* This nearly accords with Krause's estimate 

 (Muller's Archiv. 1837.) who found the mean 

 weight in five instances to be 354-4 grains, or five 

 drachms, two scruples and fourteen grains. 



