548 MALE ORGANS OF GENERATION. [CHAP, xxxvil. 



half. The tail alone possesses the power of movement, and the force 

 of the motion is sufficient to move objects many times the weight 

 of the spermatozoon. 



The movements are stopped by all those solutions which act 

 chemically upon the spermatic particle. In water, the activity of 

 the movements is at first increased, but it soon stops altogether, 

 probably in consequence of endosmosis. Urine very soon puts a 

 stop to the movements. The electric spark instantly stops the 

 motions; but, according to Prevost, galvanism exerts no action 

 upon them. 



After spermatozoa have become quite motionless, and appear to 

 be dead, movements may be excited by the addition of concen- 

 trated solutions of different substances, such as sugar, albumen, 

 urea, and various salts. Caustic alkalies, in various degrees of con- 

 centration from -fa to -f-Q, are special excitants of the movements. 

 Moreover, Kolliker states, that semen dried in indifferent sub- 

 stances and in saline solutions, in certain cases may have its 

 motion restored by dilution with the same fluid or with water. 

 The motions cease in a high or low temperature. 



In the interior of the female organs of generation, the move- 

 ments continue for a longer period than in any other situation. 

 In the receptacula seminis of insects, spermatozoa have been 

 known to retain their power of movement for many months after 

 they had been discharged by the male, and in the higher mammalia, 

 the movement continues in the mucus lining the generative organs 

 of the female for many days after copulation. 



It must be borne in mind, that the semen does not consist only 

 of the secretion of the testicle, but that it also contains the secre- 

 tions of the prostate, vesiculse seminales, and Cowper's glands. 

 What purposes these different secretions serve, it is difficult to say ; 

 but it is probable that they merely effect the dilution of the fluid 

 in which the spermatozoa move, and thus render it a more favorable 

 medium for their diffusion. 



The movements of the spermatozoa have been regarded by some 

 as due simply to the existence of endosmotic currents, while other 

 authorities have attributed them rather to the inherent contractile 

 property of the tissue of which they are composed. 



The action of certain saline solutions upon these movements, 

 does not seem, to us, to place this question in a much clearer point 

 of view ; since the mere physical alteration occurring in their con- 

 tents would alone be sufficient to excite the contraction of the 

 tissue of the spermatozoon. 



