9061 9 
No. 3.—SPERMATOGENESIS OF THE BUTTERFL1", 
PAPILIO RUTULUS. 
BY JOHN P. MUNSON, PH. D. 
Introduction. 
“Spermatogenesis of Lepidoptera ” is frequently referred to in 
cytological literature. Yet there is hardly anything that can be called 
a complete account of any one form. The work of early observers 
is especially fragmentary and scattered, so much so that it now can 
have but a historical interest, showing as it does the effect of super¬ 
ficial observation and poor technique, as well as lack of acquaintance 
with the more fundamental cell problems which recent development 
of the science has brought so prominently to mind. 
More recent writers show considerable improvement in most of 
these repects, yet I believe that it may be affirmed of insect sperma¬ 
togenesis as a whole that observers have been so preoccupied with 
some one special problem such as the phase of reduction for instance, 
as to make their work incomplete in other respects. In many of these 
later works, too, judged by their plates, the irregular outlines and 
distorted internal structures of the cells suggest imperfect fixation. 
For a number of years I have been studying the spermatogenesis 
of Papilio rutulus (pi. 12, fig. 1) not with any one single problem 
especially in view, but with the aim of ascertaining the entire life his¬ 
tory of its sperm cell, its various phases of development, its mode of 
growth and differentiation, the history of its several parts, and its 
relation to the organism. 
The sperm cell, it seems to me, is a most instructive cell for such a 
study, for it shows remarkable external and internal changes, leading 
up to a highly specialized form well adapted to its special function. 
Its connection with a gland, also, ought to commend it to the attention 
of those who do not hesitate to publish startling conclusions regarding 
life in general from studies on secretion products. 1 
1 Says Matthews (’99): “ The foregoing hypothesis makes possible a picture of cell life 
which avoids altogether the assumption of any peculiarly ‘ vital ’ substance, as dis¬ 
tinct from lifeless, and also, as I believe, that of any peculiar supra-molecular living 
units, such as the ‘ physiological units/ ‘ pangens ’ or ‘ biophores/ ” 
