232 
ME. NEWPORT ON THE IMPREGNATION OF THE OVUM, AND 
only into the chamber, but also into the substance of the yelk ; and as soon as I was 
satisfied of it, the following- precise observations were made. 
First set of observations. — An observation was begun at 1 l b 28 m a.m. with the 
temperature 60° Fahr. of the room, though possibly it was three or four degrees 
higher to the eggs, from the radiation of the lamp. 
Within five minutes an abundance of spermatozoa could be observed sticking in 
the vitelline membrane. 
At twelve minutes the number was greatly increased, and extended around all the 
circumference of the membrane within focus: some were still in motion, and passing 
slowly on through the gelatinous envelope with their characteristic serpentine move- 
ment. 
At seventeen minutes the number of the spermatozoa sticking in the vitelline 
membrane appeared to be lessened. 
At twenty-two minutes the yelk had changed its position, the dark part being 
uppermost ; and 1 could distinctly see some spermatozoa sunk in the vitelline 
membrane and shining through it, as in former observations, but I could not yet 
detect any within the cavity of the yelk : some of the bodies, both those in the yelk 
membrane and those in the jelly, were perishing, as the curling up of the tails 
showed. 
In thirty minutes the yelk had begun to separate from its envelope (forming the 
chamber ), and in the small space thus forming at the middle of its upper surface, I 
saw two spermatozoa in motion. 
At thirty-seven minutes the space was increased and more spermatozoa were in it. 
At l h 4 m the bodies were still moving, though the greater number were folded up 
both in the chamber and on the yelk, but some had their tails projecting out of the 
yelk membrane ; the chamber had attained to half of its future dimensions. 
At l h 22 m all motion had ceased, and there was a heaving of the yelk. From this 
period till segmentation began, the spermatozoa in the chamber became gradually 
fainter, till they appeared to change into fine elementary granules, and then disap- 
peared ; but some of those that entered the dark surface of the yelk remained for more 
than twenty minutes after its first cleavage, whilst others that were sticking in the 
vitelline membrane were perceptible for many hours. 
In the glass box were three other eggs, in all of which the same facts could be 
noted. The segmentation of the yelk began at the end of three hours and thirty 
minutes at the temperature stated. I may mention, that in each egg two spherical 
bodies, to be presently described, were present, and that these exist in all perfectly or 
imperfectly fecundated eggs. 
The observations were repeated on the evening of the same day on a set of four 
eggs ; and were repeated on the three following days with precisely similar results. 
Second set of observations . — I now proposed to vary the conditions of the eggs 
by having a temperature of the room of 64° Fahr., there being the corresponding 
