CHAPTER III. 



THE SPERMATIC FLUID, AND THE MALE ORGANS OF 

 GENERATION. 



mature egg- is not by itself capable of being developed into an 

 1- embryo. If simply discharged from the ovary and carried through 

 the oviducts to the exterior, it dies and is decomposed, like any other 

 part of the body separated from its connections. It is only when fecun- 

 dated by the spermatic fluid, that it acquires the capacity for continued 

 development. 



The product of the male generative organs is a colorless, somewhat 

 viscid, albuminous fluid, containing minute filamentous bodies, the sper- 

 matozoa. They have received thh name on account of their active and 

 continuous movement, suggesting the idea of independent animal organ- 

 ization. 



Anatomical Characters of the Spermatozoa. The spermatozoa of 

 man (Fig. 166, a) are about .045 millimetre in length, according to the 

 measurements of Kollikcr, They present at one end a somewhat flat- 

 tened, triangular-rjhaped enlargement, termed the "head," which consti- 

 tutes about one-tenth part of their length. The remaining portion is a 

 slender filamentous prolongation, called the "tail," which tapers grad- 

 ually backward, becoming toward its extremity so attenuated that it is 

 difficult to be jeen except when in motion. There is no further organ- 

 ization visible in the spermatozoon ; and it appears to consist, so far 

 as can be seen by the microscope, of a homogeneous substance. The 

 terms head and tail are not used, when describing the spermatozoon, 

 in the same sense as that in which they would be applied to the cor- 

 responding parts of an animal ; but simply for convenience, as one 

 might speak of the head of an arrow or the tail of a comet. 



In vertebrate animals, generally, the spermatozoa are similar in form 

 to those of man ; that is, they are filamentous bodies, with the ante- 

 rior extremity more or less enlarged. In the rabbit, the head is 

 roundish, and flattened, somewhat like a blood globule. In the rat (Fig. 

 166, b) it -'.s conical, often slightly curved at its anterior extremity ; and 

 the whole : permatozoon is much longer than in man, measuring nearly 

 0.20 millimetre in length. In amphibia and reptiles generally, the 

 spermatozoa PTC longer than in quadrupeds; and in Menobranchus, 

 they are (Fig. 166, c), not less than 0.5T millimetre long, about one-third 

 boing occupied by the head or enlarged portion of the filament. 



The most remarkable peculiarity of the spermatozoa, visible by the 

 microscope, is their movement. In a drop of fresh spermatic fluid, 



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