CHAP, viii.] ORGANS OF RESPIBATION AND SECRETION. 241 



self-division and mctamorpliosis of growing up not into a single 

 organ only, but into a perfect animal like that which produced it. 

 In the second place, this reproductive cell is formed with reference to 

 another kind of cell, without the concurrence of which other kind it 

 is quite unable to perform its own proper function ; while that other 

 kind of cell is formed exclusively — and with an admirable adaptation 

 of means to ends — for the purpose of aiding the proper function of the 

 first kind of cell. This reciprocal purposive relation, with the results 

 of the due carrying out of the thus related processes, are amongst 

 the most wonderful phenomena of the whole domain of Biology. 



One of the two reproductive elements here referred to is, as it were, 

 passive, and awaits the advent of the more active element. The former 

 is the female product ; the latter is the product of the male. 



In order, then, to effect reproduction, distinct sexual organs are 

 required for the formation (secretion) of these two elements. But it is 

 also evident that other organs are needed whereby the juxtaposition 

 of these elements may be effected, and thus it is clear that the genera- 

 tive organs must be of two kinds: (1) internal organs, which concern 

 the formation of these clem.ents themselves, and (2) external organs, 

 which concern their transmission and conjunction. These organs 

 may be expected to be different in the two sexes, as is in fact the 

 case, and thus we have to consider the external and internal gene- 

 rative organs, both of the male and of the female sex, 



§ 20. The MALE GENERATIVE ORGANS of the Cat cousist, in the 

 first place, of two glandular structures, the testes (which are the 

 essential male organs, since it is they which secrete the male gene- 

 rative element). 



Two tubes, one from each testis, called the rasa deferentia, open 

 into that median canal, the urethra, which, as we have already seen, 

 proceeds from the anterior orifice of the bladder. This canal also 

 receives the products of certain accessory glandular structures, and 

 proceeds to traverse that median external body, the penis, which 

 latter serves as the channel of exit to the urinary secretion as well 

 as to the generative products. As it leaves the bladder, the urethra 

 is surrounded by one of the accessory structures before referred to, 

 namely, the prostate gland. The other accessory glands, called 

 Coicper's glands, are two small rounded bodies, placed one on each 

 side of the urethra and in front of the prostate gland. Each vas 

 deferens enters the urethra beside its fellow of the oj)posite side. 



The penis is a conical body, mainly composed of fibrous tissue, 

 but extremely vascular. Its tissue is of tw^o kinds, arranged 

 in three masses. One mass, median, ventral, and terminal in posi- 

 tion, is called the corptus spongiosum, and immediately invests the 

 urethra. The other kind forms two laterally and dorsally situated 

 masses, called the corpora cavernosa, which are placed side by side, 

 and form the bulk of the organ, which is attached by its root to the 

 pubes and the part of the ischia nearest the symphysis pubis. The 

 distal end of the organ is called the glans, and is an expansion^ of the 



corpus spongiosum. It is conical and pointed, and has at its ex- 



11 



