AND ON THE DIRECT AGENCY OF THE SPERMATOZOON. 263 



the body of each testis, but scarcely a single spermatozoon. The few spermatozoa 

 which remained were most of them dead, and decomposition appeared to have com- 

 menced in them, and there was a large proportion of active molecules. Amongst these 

 were one or two spermatozoa still in action, and the. molecules were accumulated 

 around them by the attraction of the current in the fluid, induced by the ciliary action 

 of the tail, and were propelled onwards, frequently in a spiral direction, from the base 

 of the tail to the anterior extremity of the body ; thus showing that the motions 

 around the spermatozoon are due to the action of the filamentous tail, flexed upon, 

 and twisted spirally round the body ; in accordance with the observation of WAGNER 

 and LEUCKARDT. 



But it has been remarked, in opposition to the view, that power of motion in the 

 spermatozoon is essential to its function, that motion is not detected, or but very 

 faintly, in many instances in which the spermatozoa are united into simple and 

 uniform cords, as they often are in the deferential vessels of insects ; and that then 

 only a slight waving, or trembling of the mass, the consequence of hygroscopic con- 

 ditions induced by the fluid around, is, under such circumstances, observed. An 

 aggregation of the spermatozoa into cords takes place in the Tritons as well as in 

 insects. When the semen is expelled by the Triton at the time of conjugation, it is 

 composed almost entirely of white cord-like, flocculent masses of spermatozoa, which, 

 at that moment, exhibit only the faint undulatory motion noticed in them while still 

 within the deferential vessels. Yet, immediately after these masses are ejected from 

 the vessels, and are in contact with water, at the moment of being received into the 

 cloaca of the female, as I shall hereafter have occasion to show, the motions of the 

 spermatozoa are not only greatly increased, but that peculiar vibratory ciliary action 

 of the tail, which, while the spermatozoa are still within the seminal ducts is very in- 

 distinct, and perhaps can scarcely be said to occur is immediately set up, and the 

 motion of the body of the spermatozoon is changed from the undulatory action before 

 observed, to the jerking or watch-spring movement pointed out by observers, and 

 thought to be the motion peculiar to the spermatozoon of this class of animals. 



Thus then, the fact of only a slight wavy motion of the spermatozoon being per- 

 ceived in some cases, ceases to be of importance, as an argument against the view 

 that motion is closely connected with the function, since it is evident that the true 

 spermatic force is not set up until the spermatozoa have become more or less separated 

 from each other, through their residence in some fluid vehicle. The movements of 

 the spermatozoon in insects are very similar to those of the spermatozoon of the 

 Triton, and the circumstances which affect both are in full accordance with the 

 fact of the existence of, and the necessity for, a distinct liquor seminis, as part of 

 the normal composition of the seminal fluid, in the Mammalia; while this portion of 

 the fluid is not needed, and consequently is almost entirely absent in the Amphibia, 

 Fishes and most Invertebrata. A comparison of the facts in the two divisions of 

 animals seems to point to the true nature and use of the liquor seminis, as being that 



