PLACENTAL GENERATIVE ORGANS MALE. 833 



the commencement of the urethra, into which it discharges its secretion 

 by numerous small ducts ; and this is the most common arrangement 

 throughout the Mammiferous orders. 



(2466.) In Ruminants, Solipeds, and in the Elephant, there are two 

 or even four prostates, of a very different kind/each gland having a 

 central cavity, into which smaller cavities open by wide orifices. In 

 these creatures, therefore, the prostatic secretion accumulates in the 

 interior of the gland, from whence it is conveyed into the urethra by 

 appropriate excretory canals. 



(2467.) In most of the Rodentia, in the Mole, and in the Hedgehog, 

 the structure of the prostate is so peculiar that many distinguished 

 comparative anatomists refuse to apply the same name to organs that 

 obviously represent the gland we are describing, preferring, with Cuvier, 

 to call them " accessory vesicles" 



(2468.) In the Hedgehog, the prostate is replaced by two large masses 

 (fig. 419, A, d d), each composed of parallel, flexuous, and branched 

 tubes, all of which unite into ducts common to the whole group, whereby 

 the fluid elaborated is conveyed into the urethra through minute orifices 

 (fig. 419, B,^). 



(2469.) A third set of auxiliary secreting bodies, very generally met 

 with, are called by the name of " Cowper's glands." These in our own 

 species are very small, not exceeding the size of a pea ; but in many 

 quadrupeds they are much more largely developed. In the Hedgehog 

 (fig. 419, A,/) they are obviously composed of convoluted tubes, and their 

 ducts open by distinct apertures (B, g g) into the floor of the urethra. 



(2470.) The canal of the urethra, through which the urine as well as 

 the generative secretions are expelled from the body of the male Mammal, 

 is a complete tube, and no longer a mere furrow, as we have seen it 

 to be in all the Ovipara possessed of an intromittent apparatus. It 

 extends from the neck of the bladder to the extremity of the penis ; but 

 in this course, owing to its relations with the surrounding parts, it will 

 be necessary to consider it as divisible into two or three distinct por- 

 tions, each of which offers peculiarities worthy of remark. The first 

 part of the urethral tube is not unfrequently, as in the human subject, 

 more or less completely surrounded by the prostate gland, and in such 

 cases merits the name of " prostatic portion ;" but where, as in the 

 Hedgehog, the prostates do not enclose the commencement of the canal, 

 this division of the urethra does not exist. 



(2471.) The second is the " muscular portion," extending from the 

 prostate to the root of the penis ; and it is into this part that all the ge- 

 nerative secretions are poured from their respective ducts (fig. 419,B,6, c, 

 e f g, h). Externally this division of the urethra is enclosed by strong 

 muscles (fig. 419, A, i i), which by their convulsive contractions forcibly 

 ejaculate the different fluids concerned in impregnation, and thus secure 

 an efficient intromission of the seminal liquor into the female organs. 



