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 tria s, 
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 Sharpev 
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 m 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 m 
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 m 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. 
