THE EGG 25 
around the stalk of the capsule, seemed to exert some pressure 
on it, in other cases the ruptured capsule still partly enclosed 
the egg which projected from the opening; in others finally 
the empty capsule had just deposited the egg in the entrance of 
the oviduct.” 
The existence of double-yolked eggs renders it probable that 
the oviduct can pick up eggs that have escaped into the body- 
cavity. But in some cases ova that escape into the body-cavity 
undergo resorption there. 
Immediately after the ovum is received by the oviduct. it 
appears to become softer and more flexible (Coste). The upper- 
most portion of the oviduct then secretes a special layer of albu- 
men which adheres closely to the vitelline membrane and _ is 
prolonged in two strands, one extending up and the other down 
the oviduct; these strands become the chalazze; the layer to which 
they are attached may, therefore, be called the chalaziferous 
layer (Coste) of the albumen. The ovum then passes down the 
oviduct, rotating on the chalazal axis, and thus describing a 
spiral path; the albumen which is secreted abundantly in advance 
of the ovum is therefore wrapped around the chalaziferous layer 
and chalaze in successive spiral layers and the chalaze are re- 
volved in spiral turns. The main factor in propulsion of the 
ovum along the oviduct appears to be the peristaltic movements 
of the latter; it is probable that the cilia which line the cavity 
have something to do with the rotation of the ovum on its chalazal 
axis. 
The line joining the attachments of the chalaze is at right 
angles to the main axis of the ovum (that passing through the 
germinal disc); it is obvious, therefore, that there must be some 
antecedent condition that determines the position of the ovum 
in the oviduct; probably the position of the ovum in the follicle, 
7.e., the relation of the germinal dise to: the stigma, for the fol- 
licular orientation is apparently preserved in the oviduct. The 
question is of considerable importance because, as we shall see, the 
axis of the embryo is later bisected by a plane passing through 
the chalaze, and is therefore certainly determined at the time 
that the chalaze are formed. Is the embryonic axis determined 
before or after ovulation, and how is it determined in either event ? 
This question, to which there is at present no answer, furnishes 
an interesting problem for investigation. 
