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



whether any, and which of these eggs had been fecundated. At the expiration of one 

 hour and twenty minutes, the temperature being 54 FAHR., the chamber was beginning 

 to be formed in the two eggs in which I had seen spermatozoa sticking in the vitel- 

 lary membrane, and these bodies were still readily detected in them, and continued 

 to be so for two or three hours afterwards. These two eggs ultimately produced 

 embryos. But no change took place in any of the thirteen eggs, in which I could 

 not detect spermatozoa, no respiratory chamber was formed within, nor was any 

 embryo produced. It was evident, therefore, that these had not been fecundated, 

 and it is probable that the whole of the detached eggs were those which had last 

 been ejected from the oviducts, possibly after the act of fecundation by the male 

 had been completed. Having found spermatozoa in two only of these detached eggs, 

 I then examined several of those from the mass. In each of them I found numerous 

 spermatozoa sticking around the yelk membrane, and very many, in the clear space 

 between the membrane and the granular middle portion of the envelope, which had 

 not arrived at the membrane, and in every instance the eggs had been fecundated, as 

 the chamber was being formed at the time of examination, about an hour and a 

 quarter after the eggs had been deposited, so that the act of penetration by the sper- 

 matozoon through the envelopes as far as the vitellary membrane, seemed thus to be 

 clearly established as connected with the act of fecundation. This was the case 

 with all the eggs taken from the upper and middle portion of the mass. But in a 

 very few eggs taken from the sides of the mass, I was not able to detect any sperma- 

 tozoa, within the envelopes, or found only solitary instances of them. In these cases 

 it was remarkable that no chamber had yet been formed above the yelk, although in 

 some, in which spermatozoa were detected, it commenced at a later period, so that 

 these appeared to confirm the deduction from experiment with reference to quantity 

 of influence, or number of spermatozoa required to effect fecundation ; while the 

 penetration of the spermatozoa, as far as the vitellary membrane, and the subsequent 

 development of the chamber above the yelk, appeared in the relation of cause and 

 consequence, direct or indirect. I could not then observe, in the eggs thus examined, 

 any penetration by the spermatozoa completely through the vitellary membrane into 

 the substance of the yelk ; although numerous spermatozoa were attached, by their 

 larger ends, to every portion of the membrane, sticking out from it at right angles, 

 with what, at first, appeared to be a knob or knot at the distal end, or rather as if that 

 part of the spermatozoon had been shrivelled up or scorched. This appearance, as 

 I subsequently found, was due to a loop, or distortion of the tail of the spermatozoon, 

 consequent, apparently, on the death of this body. It was this looping of the tail 

 which gave the appearance of a thick end to this part of the spermatic body first 

 detected within the envelopes in a previous observation. All the spermatozoa seen 

 in connexion with the vitellary membrane were perfectly motionless ; so that when 

 the looping of the tail has taken place the fecundatory influence of these bodies may 

 be held to have been already exercised and exhausted. 



