238 
MR. NEWPORT ON THE IMPREGNATION OF THE OVUM, AND 
cleavage of the egg is at right angles to the line of view the spherical bodies suddenly 
disappear, and are seen again only when the crucial or second cleft is about to begin. 
I may state, that in the eggs under observation, as well as in others examined both 
before and since, I found, with but very rare exceptions, that both spherical bodies pass 
together to the same side of the yelk in a line with the entrance of the canal, and 
one at a little distance behind the other ; and that after the completion of the cleavage 
of the yelk at right angles to the line of sight, the bodies make their appearance 
again at the spot where they disappeared, and never at any other part of the yelk. 
At the end of the fourth hour the first cleft was finished, and the yelk mass con- 
tracting at right angles to the cleft, and extending in its direction, the two bodies 
were again brought into view almost at the very spot at which they disappeared. 
The same was observed in each egg. This transit, which may be regarded as an 
indisputable fact, will set aside the opinion that the bodies enter the yelk, and become 
the foundation of the nuclei of the different parts into which the yelk splits. 
It may here be mentioned, with reference to these bodies, that they occasionally 
are more or less completely detached for a time from the yelk mass during the forma- 
tion of the chamber. In some instances too, they appeared to be absent, as they 
were not in the usual place, but I found them afterwards adhering temporarily to the 
inner surface of the vitelline membrane at the point with which they were in approxi- 
mation at the time of fecundation ; in this position they remained till after the first 
segmentation of the yelk was completed, and then being detached, apparently by the 
movement of the yelk within its envelope, occupied their usual place in the first 
furrow. Eggs, with the exceptional condition above described, have always produced 
embryos ; so that whilst we doubt whether the spherical bodies are necessarily con- 
nected with the yelk-changes, we see some analogy with the corresponding bodies 
observed in several of the mollusca, in which they are removed from the yelk during 
the time it is undergoing the commotion of its first great divisions. In the ovum 
of the Rabbit (Barry) and in that of the Dog (Bischoff) they are suspended in 
the fluid, quite free of the yelk, during the first divisions ; they are also on one 
side of the yelk, usually in the cleft between the primary divisions of the mass ; and 
they continue to be seen at the same place, as in the Amphibia, until about the fourth 
or fifth subdivision, when they are suddenly lost. 
At 4 h 15 m , when the second crucial division of the yelk was nearly completed, I 
found that the granulated or anterior spherical body floated in the fluid in the first 
formed furrow, and was as yet unchanged in appearance, saving only that its contents 
seemed to be divided into two masses ; whilst the nucleated or posterior body had 
already undergone some change, since there appeared in its place a group of four 
distinct cells: these cells I am disposed to believe, in the absence of proof not yet 
obtained, were the progeny of the nucleated body that had disappeared. 
After this stage the tracing of the vesicles was more difficult. The granulated or 
anterior body, still unchanged, is seen at the same place when the yelk undergoes its 
