KARYOKINESIS AND ITS RELATION TO FERTILIZATION. 28] 
outer perivitelline layer and the “‘liquor perivitellinus,” which will give rise 
to the inner perivitelline layer, have been formed from the egg. The first 
directive corpuscle is seen resting against the outer perivitelline layer, and 
contains dark chromatin bodies. The second directive corpuscle, which is in 
the course of extrusion, shows two dark granular chromatin bodies (micro- 
somes), and is connected by means of delicate thread with the remnant of the 
germinal vesicle, the ‘‘egg-nucleus”’ (female pronucleus), which also contains 
chromatin bodies. Nearly in the centre of the vitellus is the ‘“ sperm- 
nucleus ”” (male pronucleus), derived from the intruded spermatozoon. 
