12 
Eames . — The Morphology of Agathis australis. 
escape pollination. The jacket cells break down in part. Their contents 
pass into the cytoplasm of the egg as angular, dense fragments. These fuse 
more or less and migrate towards the egg nucleus. In this condition they 
form densely granular, reticulate masses, often with narrow clear zones 
surrounding them. In some cases these bodies were seen deeply indenting 
the nuclear membrane, as in PI. II, Fig. 15. It seems doubtful if actual 
fusion occurs, as in the cases where penetration is noticed the egg nucleus is 
beginning to disorganize. Probably no significance can be attached to this 
phenomenon, although a suggestion is perhaps given of parthenogenesis, or 
of double fertilization. This condition is found only in archegonia that 
have not been approached by male cells, and no evidence appeared of the 
migration of nuclei, or of large portions of the contents of the jacket cells 
under normal conditions. 
As shown in PI. Ill, Fig. 27 the fusion nucleus has a marked nuclear 
membrane, and is loosely invested by a prominent sheath of kinoplasm. It 
maintains its position near the centre of the archegonium, and there gives 
rise rapidly to a large proembryo. This behaviour in the early history of 
proembryonic development is in great contrast to the conditions in other 
groups of Conifers where the fusion nucleus or its division products, two, 
four, or eight nuclei, sink to the bottom of the archegonium, and there 
continue the growth of the proembryo. 
The spindle of the first division is small and intranuclear, as PI. II, 
Fig. 21 shows. The two daughter nuclei (Fig. 22) are of good size. They 
are still free from the kinoplasmic sheath. But with the division into four 
the kinoplasm is invaded, and the nuclei become distributed throughout a uni- 
form mass of dense cytoplasm. PI. Ill, Fig. 29 exhibits this spherical mass 
with its nuclei (two only of the four visible) suspended near the centre of the 
archegonium. Another rapid simultaneous division forms eight nuclei of 
good size. These are distributed uniformly throughout the proembryo — 
compare Fig. 30, four nuclei showing. In the continuation of the free 
nuclear division the mitoses resulting in the formation of sixteen and thirty- 
two nuclei do not occur so rapidly, and are not always simultaneous within 
the group — some divisions being quite complete when others are only 
beginning. 
After the fifth consecutive division in the proembryo free nuclear 
mitosis frequently ceases, and wall-formation soon occurs ; but a sixth com- 
plete division of this sort was found in a few cases, and an irregular increase 
in nuclei may take place at this time. Thus the proembryo in its final 
stage before wall-formation may possess anywhere from thirty-two to 
sixty-four nuclei, thirty-two being most common. Fig. 36 represents the 
sixteen-, and Fig. 23 the thirty-two-nuclear stage. The nuclei are large, 
rounded, and frequently binucleolate. At this time they are evenly distri- 
buted throughout the entire mass, those parietally situated often causing 
