Reviews and Records in Anatomy and Physiology. 397 
observation of physical facts, and we regard these important data 
worthy of full trust considering the source from which they come, 
This author discusses briefly the question of the nature of the im- 
pregnative power, and from the fact that the spermatic particles 
are sometimes seen to disappear on the surface of the egg-envel- 
opes, he thinks it may be fair to conclude that the agency of this 
body is material in its operation; on the other hand, the fact ofa 
mere momentary contact producing changes in the ovum, suggests 
in his mind the so-called catalytic power of certain known bodies. 
But he thinks that neither this last, nor endosmosis, are sufficient 
to account for the phenomena of this grand act. 
The view of Kéber, the last of the writers we have cited, has 
at least the merit of being unique if nothing more. As long ago 
as 1838, Martin Barry* announced that he had observed spermatic 
particles within the ovum. It should be mentioned however, 
that long previons to this, Prevost and Dumasf in their researches 
found these particles within the envelopes of the eggs of frogs. 
ut Keber’s alleged discovery is, that the introduction of the sper- 
matic particles within the ovum, takes place through a special 
opening, a kind of micropyle, or an infundibuliform passage. 
This discovery was made upon the eggs of mussels (Unio and An- 
odonta), and that I may furnish a correct idea of its formation and 
relations, I will quote some of his conclusions. After describing 
the formation of the eggs and sperm of these animals, he pro- 
ceeds :— 
“3d. At the procreative season, there arises from the eggs, 
becomes obliterated. 
“ Ath, After this, and sometimes even before, the albuminous 
and vitelline membranes coalesce at the point of the micropyle ; 
then the vitelline sac dehisces, and thereby the spermatic particle 
is received and enclosed in the very interior of the egg.” —(p. 107.) 
pon this sneceeds a description of the more or less Minute 
changes which are alleged to supervene upon these processes, 
such as the disappearance of the micropyle, the disintegration of 
* Barry, Philos. Transact., 1840, pt. ii, p. 582.—1843, pt. i, p. 83. 
+ Prevost and Dumas, Ann. d, Se. Nat, ii, p. 233. 
