CYTOPLASMIC INCLUSIONS OF THE GEKM-CELLS. 40 $ 
but also for liis many kindnesses to me in the years during' 
which, a student, I had the privilege of working under him. 
This work was done in the Department of Physiology 
during a part of the time 1 relieved Dr. Scott, and I owe 
my warmest thanks 1 to Prof. Sherrington for the way in 
which he facilitated my task and encouraged my work. 
A good deal of my material was derived from Prof. 
Poulton’s Department, and his assistants, Mr. Hamm and 
Mr. Britten, aided me considerably in finding suitable species. 
It had been intended in the first place to study the 
chromosomes as well as the cytoplasmic bodies, but as the 
work proceeded I found that the latter structures needed 
examination more than the former, and it was not possible 
to study both satisfactorily at the same time. This paper 
therefore deals exclusively with plasmatic inclusions. 
Previous Work. 
It is not intended to give here an extended account of the 
great body of work done on the spermatogenesis of the Lepi- 
doptera. The oogenesis has hardly been treated at all by 
those observers who have examined the spermatogenesis ; 
the former provides problems somewhat more difficult to 
follow out, and perhaps also less attractive, for in the early 
stages it is difficult to find individual oogonia and oocytes 
sufficiently clear for study, so crowded are they. In this 
paper I have endeavoured, as far as I found possible, to find 
homologous processes going on in the germ-cells of both sexes. 
Of all the work done on the spermatogenesis of the Lepi- 
doptera, that of Meves (1) stands out most prominently ; Meves 
was not occupied so much with chromosomes as with the cell 
inclusions and the metamorphosis of spermatid into sperma- 
tozoon. In all his work on the spermatogenesis, Meves has 
overlooked important facts concerning the cytoplasmic bodies, 
some of which he has not found, and, moreover, his modified 
Flemming iron heematoxylin technique is not calculated to 
1 I have also to thank Prof. G. C. Bourne for some excellent 
suggestions with regard to the text. 
