408 
J. BRONTE GATENBY. 
Introduction. 
Since the numerous important papers on the spermato- 
genesis of many animals have shown that the elaborate series 
of events leading to the metamorphosis of the spermato- 
gonium into the spermatozoon entail not only great changes 
in the nucleus, but also the presence of a number of definite 
eytoplasmic bodies whose movements and staining powers 
are as regular as those of the nucleus and centrosomes them- 
selves, it becomes increasingly evident that it is incorrect to 
look upon the sperm as simply the vehicle for the chromatin 
of the nucleus and for the centrosome. There are other bodies 
whose behaviour merits the belief that they are concerned in 
the transmission of some qualities to the egg, and therefore 
to the offspring. The Lepidoptera have several such bodies 
whose ultimate fate is obscure. Moreover, they are not 
properly understood, and their relationship to chromatin, if 
any, has not been determined. An examination of the ferti- 
lisation of the Lepidopteran has not hitherto been carried out 
with the intention of ascertaining what role these bodies play 
in this important stage of the germ cell cycle, and such a 
field would probably yield useful results. The spermatozoon 
becomes in later stages of formation such a difficult object to 
study that there is no doubt that the only manner in which 
one could feel sure as to whether any of the several bodies 
really reached the egg would be to examine fertilisation 
stages fixed in suitable media, which should be absolutely 
free from certain acids. This unfortunately introduces great 
difficulties of technique, for the chorion of insect eggs is 
extremely difficult of penetration by any fixatives except 
those containing the ingredients, which experience has shown 
are mostly hurtful to most cytoplasmic inclusions. Neverthe- 
less, there are ways in which such difficulties can be over- 
come, and subsequent research will be done on this work. 
The subject of this research was suggested by Dr. E. S. 
Goodrich, whom I have to thank not only for his suggestions* 
