710 THE GENERATIVE ORGANS. 
chamber could enter into the formation of the eggs, so that, 
although authors still speak of the terminal chamber as the 
germ chamber, it is evident that, as Lubbock maintained, these 
cells become yelk-cells if the ova in the terminal portion of the 
oviduct ever become mature. 
Balfour [48], the most learned embryologist of his day, in 
188r wrote: ‘The following points need elucidation with 
regard to the ova of Insects: 
‘(r) The relation of the germogen to the vitellogen, and (2) 
the relation of the yelk to the germ.’ It is evident, therefore, 
that he was dissatisfied with the explanation given in the 
voluminous literature of the subject, and regarded the ques- 
tions at issue as unsettled, and I am not aware of any investi- 
gations which have been made since then, with the exception 
of my own, which tend to throw any further light on the 
subject. 
The remarkable corpuscles first found imbedded in the 
epithelium of the parovaria by myself, in 1888, are so 
strikingly like the germ ova of other animals that I have no 
hesitation in regarding it as the germ-gland, just as I have no 
hesitation in regarding the great ovaries as yelk-glands. 
The question as to how these germ ova reach the yelk and 
enter the egg is a subsidiary one, but one which it is not 
difficult to answer, although it is by no means easy to find 
direct proof of the truth of the answer. 
As the eggs pass down the oviduct, each remains for a brief 
space in the sacculus, with its micropyle closely related to the 
orifices of the ducts of the parovaria. It is therefore quite 
possible for a germ ovum to enter it by the micropyle. The 
egg next passes into the uterus, and rests with its micropyle in 
immediate relation with the ducts of the spermathecz, from 
which no one doubts the sperm-cells enter the egg. 
It may be objected by some that developing ova are frequently 
found in the oviducts; but it must be remembered that such 
eggs must have been impregnated, and therefore have evidently 
been in the uterus, hence they must have passed the orifices of 
the ducts of the parovaria in their descent; and the fact that 
