Shaw . — The Fertilization of Onoclea. 285 
Fig. 7. Half per cent, chromic acid : Delafield’s haematoxylin. Fourteen hours. 
Horizontal sections of an egg. The large nucleolus is shaded lightly because it 
occurs in a lower focus than the adjacent male chromatin. 
Fig. 8. One per cent, chromic acid : Heidenhain’s haematoxylin. Fourteen 
hours. Two spermatozoids which were held in the slime outside an open 
archegonium. The cilia could be* seen, but were not drawn because they could not 
be traced to their points of attachment with certainty : some were directed back- 
ward, but most of them forward. One nucleus was broken into two and the other 
into three pieces by the razor. 
Fig. 9. One per cent, chromic acid: Heidenhain’s haematoxylin. Sixty hours. 
Egg-nucleus from an oblique horizontal section. The large nucleolus is shaded 
lightly because it is behind the male nucleus. 
Fig. 10. Half per cent, chromic acid : alum-carmine. Twelve hours. Sperma- 
tozoids held in the slime outside an archegonium, showing the nucleus and 
kinoplasm. 
Fig. 11. Half per cent, chromic acid : Delafield’s haematoxylin. Twelve hours. 
Vertical section of an egg with the enclosed spermatozoid still showing the coiled 
spiral form. 
Fig. 12. Half per cent, chromic acid: alum-carmine. Twelve hours. Hori- 
zontal section of an egg. Both the male and the female nucleus have a linin- 
network bearing chromatin bodies. The cytoplasm under most favourable 
illumination shows an alveolar or reticulate structure. 
Fig. 13. Half per cent, chromic acid: alum-carmine. Twelve hours. Vertical 
section through an egg-nucleus. x marks the direction of the archegonium 
canal. 
Fig. 14. Half per cent, chromic acid : Heidenhain’s haematoxylin. Thirty-six 
hours. Nucleus in a horizontal section. The distribution of the male nucleus is 
not much further advanced than in Fig. 12 after twelve hours. The lighter large 
nucleolus is not in the same plane as the end of the spermatozoid. 
