220 
MR. NEWPORT ON THE IMPREGNATION OF 
water they had been immersed in was coloured. I then again removed them to elear 
water. At the end of sixteen hours they had parted with more colour, but were still 
red, more especially between the inner portion of the envelope and the vitelline mem- 
brane, and the water had again acquired a red hue, thus showing that both endos- 
mose and exosmose must have taken place. 
As it might fairly be objected that these ova, changed by immersion in spirit, were 
unfitted for experiment, I made trial with others whieh had not been impregnated, 
and being infertile, had remained in water many days without giving signs of decay. 
When these were placed in the carmine solution, their envelopes became as deeply 
and thoroughly imbued with colouring matter throughout their whole substance as 
in the former ; and when placed in clear water they parted as readily with a portion 
of it, so that it M^as evident that whenever the density of the fluid in which these 
dead and infertile ova were immersed, was altered, a change by endosmose or exosmose 
immediately took place in the fluid retained mechanically in their tissues. To this 
cause, perhaps, may be ascribed the colouring of the ova in Prevost and Du.mas’s 
first experiment with ink, while other experiments, which I shall mention, made on 
living and impregnated ova, lead me to regard the colour in the experiment with 
frog’s blood as merely the result of adhesion of colouring matter to the surface. 
The immediate objects I had now in view were, to learn whether impregnation is 
effected by any direct and palpable infiltration of seminal matter through the enve- 
lopes of the ovum ; — whether the admixture of other matters with the seminal fluid 
will prevent or arrest impregnation ; — and whether the spermatozoa collected on a 
filter paper, and then placed with this in a fluid of great density, are as efficient as in 
clear water. 
With these views, I prepared a very dense solution of carmine pigment in water, 
and added parts of this to small quantities of water with ova, either before the 
seminal fluid was mixed with the water, or immediately afterwards, and 1 expected 
the results to show whether any solid particles, held in suspension in the fluid, passed 
through the envelopes. The previous trials had shown that solid particles do pass 
through the dead tissue, but it was doubtful whether the like result would occur in 
the living. 
Carmine Experiments. — Set O. March 13, 1850. Atmosphere 53° Fahr. 
No. 1. Eleven unimpregnated ova were passed into water mixed with carmine. 
The envelopes became as fully expanded, and imbibed fluid as freely as in the im- 
pregnated ova, and acquired a red tint ; but much of the colour was due to the deposi- 
tion of granules of matter on the surface, while I was unable to detect any similar 
granules within their texture. On the contrary, on removing part of the surface of 
the envelopes, the interior, although slightly reddened, exhibited an uniform appear- 
ance. 
No. 2. lliirty ova were passed into water that had been mixed with seminal fluid, 
and immediately afterwards a solution of carmine was also added. 
