236 
MR. NEWPORT ON THE IMPREGNATION OF THE OVUM, AND 
At thirty-seven minutes the chamber had begun to form, and several moving- sper- 
matozoa were in it. The spherical bodies made their appearance on the surface of 
the yelk ; and when first noticed they were closely applied to it, and were surrounded 
by a small irregular heap of granules. Some of the spermatozoa remained in motion 
l h 22 m , and I have subsequently seen them alive in the chamber for a longer period. 
At l h 30 1,1 the two bodies differed somewhat in character, and one was before the 
other: the anterior or granulous one appeared to have a distinct membrane, and to 
one in the eggs of Exogena (Erstedii, which he at first looked upon as the embryo cell (in Einige Worte zur 
Entwickelungsgeschichte von Eunice. Nachworte von A. Kolliker in Zurich, Nauenberg, 1846, note). 
Quatrefages also has noticed one in Hennella (Ann. des Sciences Nat. 3 serie, tom. x. 1848, p. 177. pi. 3. 
fig. xv. xviii.), and more recently Van Beneden has seen and figured one in the eggs of a Cestoid worm, 
Echineibothrium variabile (Mem. de l’Acad. de Bruxelles, tom. xxv. p. 68, pi. 3. fig. 15. 1850). Thus the 
existence in many Invertehrata of at least one detached spherical body on the surface of the fecundated yelk, 
before segmentation, seems to point to the conclusion that these bodies have some important signification with 
reference to the future embryo. Quatrefages, who has recently directed attention to the fact of their 
occurrence, properly remarks, that their presence at this stage of development of the egg is much more general 
than it has hitherto been supposed. 
These bodies have been seen equally in the Vertebrata as in the Invertebrata. In the Vertebrata they appear 
to have been first noticed, but entirely misunderstood, by Dr. Martin Barry in the Rabbit. Although repeat- 
edly seen and figured by him (Philosophical Transactions, 1840, p. 538, Plates XXIV. XXV. and XXVI., 
figs. 185, 186, 187 and 193, 200, 206, 209, 212), imagining that the germinal vesicle does not disappear before, 
but only changes its form, becomes enlarged, and takes the place of the yelk, subsequent to fecundation, he 
conceived that these spherical bodies were the remains of the yelk, or, as he terms it, “substance” (p. 538), 
which he supposed had undergone dissolution and disappeared. Professor Bischoff however, having noticed 
these bodies in the egg of the Rabbit (Muller’s Archiv, 1841, p. 14. tab. 1. fig. 6), directed particular atten- 
tion to them (Entwickelungsgeschichte des Kaninchen-Eies, 4to. 1842, tab. 2. fig. 17 5, figs. 19, 20), and 
believed them to play an important part in the segmentation of the yelk. Subsequently to this, these spherical 
bodies were also noticed by Bischoff in the egg of the Dog (Entwickelungsgeschichte des Hunde-Eies, 4to. 
1845, tab. 1. figs. 11, 12, 13, 14); and afterwards Poucfiet, who had noticed a single vesicle, as before 
stated, in the Mollusca, gave also one only in the egg of the Rabbit, which he has equally regarded as a de- 
scendant of the germinal vesicle (Th^orie positive de l’Ovulation spontanee et de la Fecondation des Mam- 
miferes, Paris, 8vo. 1847, pi. 15. fig. 9). More recently Professor Bischoff has noticed, as in the Rabbit and 
Dog, two of these spherical bodies in the egg of the Guinea Pig (Entwickelungsgeschichte des Meerschwcin- 
chens, 4to. 1852, tab. 1. figs. 5, 6), and I have also found two in the egg of the Frog (Philosophical Transactions, 
1853, p. 247). It is thus evident that the appearance of certain spherical bodies on the surface of the yelk, 
between it and the zona pellucida subsequent to fecundation, and after the yelk has become contracted and 
ceases to fill the entire zone, and before any subdivision of the yelk is commenced, is a general and perhaps 
universal occurrence in the fecundated egg both of vertebrated and invertebrated animals, but of the significa- 
tion of these bodies very different opinions are entertained. 
Dr. Bischoff, in his most recent work on the Guinea Pig, states that he formerly believed these bodies to 
play an important part in the segmentation of the yelk, and that the view he then held has been adopted by 
Loven; while F. Muller conceives that these vesicles determine the direction of the segmentation of the 
yelk. Ratiike, on the other hand, regards these vesicles but as accidental occurrences, and of no organic or 
developmental importance (Erichson’s Archives, 1848, p. 187), a view in which he is supported by Desor, in 
some observations on Nemertes (Muller’s Archiv, 1848, p. 511), and to which Professor Bischoff himself 
states he is now somewhat inclined, although he properly remarks that the regularity of the appearance of 
these vesicles at a definite stage of development of the egg is not favourable to such an opinion ( loc . cit. p. 19 ). 
