TESTICLE (NORMAL ANATOMY). 



984 



pleted. Congenital hernia, or hydrocele is 

 the result of a failure in this process ; arid 

 other forms of hydrocele are occasioned by 

 imperfect obliteration of the canal. 



Much difference of opinion exists as to the 

 immediate cause of the transition of the tes- 

 ticle. Hunter, Meckel, and others came to the 

 conclusion that the muscular fibres of the 

 cremaster are insufficient to bring the testicle 

 further than the abdominal ring and complete 

 the passage. They were not, however, ac- 

 quainted with the attachment of this muscle to 

 the pubis external to the ring, or it would be 

 difficult to understand why Mr. Hunter, after 

 arriving at the conviction that the cremaster 

 passes to the testicle whilst in the abdomen, 

 chiefly from analogy, was not induced by the 

 same process of reasoning to conclude, that a 

 muscle capable of changing the position of 

 the testicle in brute animals, would be ade- 

 quate to accomplish the same office in the 

 human foetus. The necessity for some active 

 agent to effect this change in the latter would 

 appear to be greater even than in the lower 

 animals, since, in the usual position of the 

 foetus in utero, the passage of the testicle 

 is contrary to gravitation,* and unaided by 

 the movements of respiration. Now, when 

 we consider the attachments and connec- 

 tions of this muscle in the foetus ; the per- 

 fect development of its fibres, as ascertained 

 by microscopical examination ; and the circum- 

 stance that there are no other means, no other 

 motive powers, by which this change can be 

 effected, or in any way promoted, 1 think there 

 is no reason to doubt that the cremaster ex- 

 ecutes the same office in the human embryo, 

 as that which it undoubtedly performs in cer- 

 tain brute animals at a particular season. 

 The fibres proceeding from Poupart's liga- 

 ment, and the obliquus interims, tend to guide 

 the gland into the inguinal canal ; those at- 

 tached to the os pubis to draw it outside 

 the abdominal ring ; and the process extend- 

 ing to the bottom of the scrotum, to direct it 

 to its final destination. As the process ap- 

 proaches completion, the muscular fibres 

 which perform so important a part in it gra- 

 dually become everted, and acquire the new 

 functions of elevating, supporting, and com- 

 pressing the gland. 



The Functions of the Testicle. The sperm 

 or fluid secreted by the testicle has been con- 

 sidered in the article (SEMEN). On survey- 

 ing the structure of this gland, we cannot fail 

 to remark the great extent of secreting surface 

 afforded by the numerous, long, and tortuous 

 tubuli, and the length and complexity of the 

 excretory duct through which the seminal 

 fluid has to pass. The extent of this duct is, 

 indeed, so remarkable, that many physiologists 

 have been led to suppose that the semen is 



Owen, being the only brute animal in which the 

 tunica vaginalis forms a shut sac. 



* For this reason I have departed from the usual 

 custom of English anatomists, and avoided describ- 

 ing the change in the position of the testicle, as 

 the descent, 



further elaborated or perfected in its passage 

 through the convolutions constituting the 

 epididymis. An examination of the spermatic 

 fluid taken from the testicle and its duct 

 both in man and in the lower animals, under 

 all circumstances and at all periods, and the 

 varving state of the discharge in cases of 

 spermatic fistula, leave little room to doubt 

 that secretion takes place actively only dur- 

 ing the periods of sexual excitement, or under 

 the influence of sexual feelings and desires. 

 From birth to the period of puberty the 

 testicles remain small, and grow but little 

 in proportion to other parts ; but as the 

 body, on the arrival of puberty, becomes 

 stamped with the characters of the male sex, 

 they rapidly enlarge, their glandular structure 

 becomes much more developed, and, being 

 excited, these organs begin to exercise the 

 office of secretion, no spermatozoa being found 

 in them until this period arrives. The age at 

 which the testicles thus become developed 

 varies in different climates, and in different 

 constitutions, and is influenced by the mode 

 of life and circumstances in which the indivi- 

 dual is placed. The inhabitants of warm 

 climates reach the age of puberty earlier 

 than those of cold countries. In this part of 

 Europe the change takes place from the age 

 of fourteen to seventeen years, according 

 to circumstances. Unlike the inferior ani- 

 mals, the testicles in man are ready at all 

 seasons to perform their office. The de- 

 sires subside, and the secretion of semen be- 

 comes languid as life advances, though they 

 seldom cease entirely till the age of sixty-five 

 or seventy. Indeed, I have several times dis- 

 covered spermatozoa in the testicles of men 

 upwards of seventy years of age, and once in 

 the testicle of a tailor who died at the age of 

 eighty -seven. There are instances on record 

 of persons retaining the procreative faculty to 

 the age of one hundred years ; but in these 

 cases, as in the well-known instance of old 

 Parr, the general bodily powers were also pre- 

 served in a very extraordinary degree.* 



" To the use of the sexual organs for the 

 continuance of his race man is prompted by a 

 powerful instinctive desire, which he shares 

 with the lower animals. This instinct is ex- 

 cited by sensations, and these may either ori- 

 ginate in the sexual organs themselves or may 

 be excited through the organs of special sen- 

 sation. Thus in man it is most powerfully 

 aroused by impressions conveyed through the 

 sight or the touch : in many other animals, 

 the auditory and olfactive organs communi- 

 cate impressions which have an equal power ; 

 and it is not improbable that in certain mor- 

 bidly excited suites of feeling, the same may 

 be the case in ourselves. That local impres- 



* Old Parr, who lived to the great age of 152, 

 was dissected by the celebrated Harvey, and it is 

 stated, " Genitalibus erat integris, neque retructo 

 pene neque extenuato, neque scroto distento ramice 

 aquoso tit in decrepitis solet, testiculis etiam inte- 

 gris et magnis." Bettus de Ortu et Natura San- 

 guinis, p. 320. 



