160 



PROSTATE GLAND. 



tions are occasionally met with in the vesiculae 

 seminales and vasa deferentia; but, according 

 to Peschier, their analysis differs slightly from 

 prostatic concretions. Thus he found in 100 

 parts 



Phosphate of lime . . . 90'0 

 Carbonate of lime . . .2*0 

 Animal matter . . . . I'O"* 



Comparative Anatomy. Assuming the 

 prostate to be represented by a glandular 

 structure placed at or near the termination 

 of the vas deferens, it is found in many of 

 the invertebrate animals. As a general 

 rule, it is only discovered in those pos- 

 sessed of an intromittent organ ; this, how- 

 ever is not invariable. In the medicinal leech, 

 among the annellata, according to Owen and 

 Brandt, the two vasa deferentia and the two 

 sacculated vesiculae seminales send their ducts 

 to a common prostatic body, from which the 

 penis is continued. " In the centipede, 

 among myriapoda, a minute efferent tube is 

 continued from both ends of each testis, which 

 tubes unite with those of the adjoining organ, 

 and ultimately form a single vas deferens, 

 which, having received the ducts of three pairs 

 of small prostatic glands, terminate in the 

 cloaca. In the male aphis there is a long pyri- 

 form vesicular gland attached to each lateral 

 vas deferens, and in many insects representa- 

 tives of prostatic glands communicate with 

 the ductus ejaculatorius." f In the slug, 

 among gasteropoda, the vas deferens is joined 

 by the short and simple duct of a small pros- 

 tatic sac ; and this is the case in the common 

 snail, in whom the duct is, however, longer. 

 In the cephalopoda, as in the octopus, " the 

 anterior extremity of the contractile vesicula, 

 into which the efferent duct opens, communi- 

 cates with a wide, bent, coecal tube (prostate), 

 with thick glandular parietes, and having the 

 form of a simple pouch in the sepia. The 

 prostate in the sepiola communicates by a long 

 and slender duct with the vesicute semi- 

 nales." t 



In mammalia, two varieties of prostate are 

 found, distinguishable as to structure from 

 each other : one, the cellular, in which small 

 cells open into a central cavity, from which a 

 large duct arises ; and the other, the follicular, 

 composed, as Miiller says, " of large intesti- 

 nnles, or larger ramose follicles." 



In the ape tribe, the form of the prostate is 

 larger from above downwards than from before 

 backwards, and surrounds the urethra in the 

 form of a crescent. In position, si/e, and 

 structure, it resembles that of man. In the 

 mandril some accessory lobes are found. 

 The prostate of the makis sends off two pro- 

 longations, which surround the excretory 

 ducts of the vesiculae seminales. 



In the tarsier, there are two distinct glands, 

 placed in front of the vesiculae seminales, on 

 the side of the urethra. 



The galeopit/ieci have a single prostate 



* Vogel's Pathological Anatomy of the Human 

 Body, translated by Dr. G. E. Day. 



t Owen's Lectures on the Invertebrate Animals. 



of large size, surrounding the base of the 

 vesiculae. 



In the roussette, the prostate is simple, 

 and surrounds a large portion of the circum- 

 ference of the urethra. 



In the dormouse, it surrounds the whole 

 circumference of the urethra, and is composed 

 of a number of lobules. 



In the hedgehog, the prostates are four in 

 number, and they belong to the tubular class. 

 The superior prostates are the larger, and are 

 composed of long flexuous tubes, united into 

 lobules, which form lobes, whose tubes re- 

 unite to form a single excretory duct, which 

 pierces the superior surface of the urethra. 

 They are attached by processes of the perito- 

 naeum to the abdominal muscles. (Hunter.) 

 Two other bundles of smaller size, and of a 

 rounded form, represent the inferior prostates. 

 They are composed of smaller tubes, which 

 separating in the form of a fan, pass towards 

 the circumference of the gland, and terminate 

 in ccecal ends. The excretory ducts open one 

 on either side of the veru montanum. The 

 tubes are composed of membranes of extreme 

 delicacy. 



In the mole, the prostate is single, and is 

 formed of membranous tubes folded upon 

 themselves. At the period of heat, it in- 

 creases so enormously as to exceed the 

 urinary bladder in size ; it is placed around 

 the urethra in front of the bladder. 



The prostate of the bear is confounded with 

 the dilatation of the united vasa deferentia. 

 It surrounds the beginning of the urethra, and 

 forms a bed for the canal of variable thickness, 

 according to the species. 



In the otter, weasel, and marten, it consists 

 of a thin layer, without any enlargement. In 

 the ichneumon, there is a gland of consider- 

 able size, composed of distinct lobes, situated 

 on the rectal aspect of the urethra ; each lobe 

 has a distinct duct. 



In the dog and cat, it forms a large promi- 

 nent collar around the urethra; it resembles 

 the human prostate in structure, and mode of 

 termination of its ducts. 



In the hyena, it is of large size ; and in the 

 civet it forms two tubercles in front of the in- 

 sertion of the vasa deferentia. 



In the marmott, among the rodentia, it is 

 divided into two lobes, and forms a consider- 

 able swelling around the commencement of 

 the urethra. 



The glandular covering of the vesictilne 

 seminales, which extends below the muscular 

 structure of the urethra, represents the pros- 

 tate gland in the rabbit. 



In the squirrel, it is as long as the muscular 

 portion of the urethra, of large size, ovoid in 

 shape, flattened from above, and is divided 

 into two lobes ; it adheres to the urethra by 

 two points, where its excretory ducts pene- 

 trate the canal. 



According to Miiller, in the rat genus, be- 

 sides three glands of different structure on 

 each side, the urethra is surrounded by a 

 glandular mass, consisting of bunches of vesi- 

 cles, representing the prostate. 



