286 MR. NEWPORT ON THE IMPREGNATION OF THE OVUM IN THE AMPHIBIA 



One hundred and forty -seven eggs were then placed on the topmost of the filter 

 papers, which had been employed in separating the fluid used in the preceding trials, 

 and on which were the remains of the broken-down spermatozoa, with, probably, 

 some which had not been injured. This was about four hours and a half after 

 the spermatic fluid had been obtained, so that on this ground but little success 

 could be expected. Not a single embryo was produced. 



The portion of reserved fluid which had not been triturated was then applied to 

 four eggs in separate cells, by means of the pin's head, when each of these eggs 

 became fecundated, and not only underwent segmentation, but each afterwards pro- 

 duced an embryo. As this experiment was made for the purpose of comparison with 

 the preceding, it is clear that the failure in the case of the mass of eggs on the filter 

 paper was not due to the length of time the fluid had been obtained, but to the effect 

 of trituration ; and it seems equally clear that the substance of the broken-down 

 spermatozoa dissolved in water and passed through the filter is as inefficient as the 

 liquor seminis has heretofore been proved to be*. 



These experiments were afterwards repeated, in the presence of Professors SHARPEY 

 and ELLIS, with similar results. Usually there are still some spermatozoa which 

 escape being crushed during trituration, and, being uninjured, remain on the filter 

 paper capable of effecting impregnation when eggs are passed upon it in water, as 

 was the case on the following occasion. 



Seventy eggs were first added to some filtered fluid, which resulted from the 

 trituration of spermatic fluid, and had passed through four filter papers, but not one 

 egg became affected, not one embryo was afterwards produced from them ; while of 

 sixty-two eggs placed on the topmost filter paper in water, amidst the remains of 

 broken-down spermatozoa, with many which were still active and uninjured, more 

 than one-third of the eggs became fertilized, and twenty-three afterwards produced 

 embryos. 



It was thus evident that no impregnation results from an immersion of the egg in 

 fluid which is derived from the broken-down body of the spermatozoon, mixed with 

 water, and separated from the more solid parts by filtration. But as some objections 

 may fairly be offered as to the validity of this experiment, it seemed desirable that 

 trial should be made without having recourse to filtration, and without removing 

 any portion of the destroyed spermatozoon; but, on the contrary, by applying the 

 whole of the triturated fluid immediately to the egg before it is immersed in water; 

 and at the same time to compare the result obtained with that of an experiment by 

 simple artificial impregnation, with a sample of the same spermatic fluid which had 

 not been triturated; the experiments in both cases being made at the same time, 

 and with eggs from the same female, and placed under precisely similar conditions 

 in regard to light, heat, &c. A comparison of the relative number of embryos which 

 might result from these experiments, it was thought, would show, not merely whether 



* Philosophical Transactions, 1851. 



