AND ON THE DIRECT AGENCY OF THE SPERMATOZOON. 281 



i 



are detailed in that paper; viz. that when diluted spermatic fluid, recently obtained, 

 is applied to a set of eggs, and as soon afterwards as the experiment can be made, 

 a solution of potass, of such a strength as is known by previous microscopic observa- 

 tion to have the property of instantly decomposing the spermatic body, the solution 

 being washed away quickly after its application, by repeated quantities of water, 

 to prevent its affecting the egg itself that then in some instances even when the 

 interval of time between the application of the spermatic fluid and the subsequent ap- 

 plication of the potass does not exceed a few seconds, impregnation of the egg is 

 effected; as is proved by the formation of the chamber, the segmentation of the 

 yelk, and perhaps the formation of an embryo. Further, that, all circumstances 

 being similar, excepting only that the interval of time between the application of the 

 spermatic fluid, and, subsequently, that of the solution of potass be prolonged, the 

 production of an embryo is not only more certain to take place, but the number of 

 embryos produced is increased. The now ascertained fact of almost instantaneous 

 penetration by the spermatozoon, which, as before shown, sometimes arrives at the 

 vitelline membrane in less than one minute after its application to the egg, confirms 

 the principal conclusion deduced from the potass experiments at the time they were 

 made, viz. that impregnation is commenced at the instant the spermatozoon is in con- 

 tact with the egg ; while it also seems to afford the true explanation of the nature of 

 those experiments, in which it may now be presumed that some spermatozoa had 

 actually penetrated into the substance of the envelopes before the application of the 

 solution of potass, and thus had already passed out of the reach of its destructive 

 influence, the effect of which on the egg itself was obviated by speedy dilution and 

 ablution with water. 



The potass experiments may thus be regarded as confirming by anticipation the 

 results now obtained by direct observation with the microscope, with respect to the 

 rapidity of operation by the spermatozoon; and they seem also to support the view 

 of the essentiality of the motor power of this body to its functional action. A similar 

 view may be taken, as indeed was held at the time, of the nature of the Carmine, the 

 Gum, and the Starch experiments, that the operation of these substances in preventing 

 the fecundation of the egg is entirely mechanical, and that they do so simply by offering 

 a mechanical impediment to the spermatozoon, a conclusion which seems to be fully 

 supported in the present inquiry. 



14. NATURE OF THE INFLUENCE OF THE SPERMATOZOON. 



Having seen in the preceding experiments and observations that fecundation of 

 the egg is effected by the spermatozoon only while this body retains and continues to 

 give evidence of its vitality in its power of motion, and that its vitality either may be 

 destroyed, or its operation be for a time entirely arrested by electricity and by chlo- 

 roform, the question naturally arises in what way, then, is its fecundatory influence 

 to be explained ? Is it simply by diffluence of the substance of the spermatozoon, and 

 the chemical fusion or combination of this with the contents of the egg, after the sper- 



