35 
Eames . — The Morphology of Agathis australis . 
point what relation it may bear to Agathis . It seems evident that within the 
latter genus the species selected for this investigation, A. australis , is the 
least primitive. 
Summary. 
1. Agathis australis is monoecious. Ovulate strobili appear about 
October first ; pollination occurs one year later, and fertilization thirteen 
months after pollination. 
2. The mature gametophyte is club-shaped, the larger upper section 
bearing numerous scattered archegonia. 
3. The archegonial jacket is incomplete near the neck, the cells 
of which are thick walled and form a complex which resists the entrance 
of the pollen-tube. 
4. The pollen germinates in the axil of the cone scale, no micropyle 
being differentiated at that time. Long, branching haustorial pollen-tubes 
penetrate the cone axis, also the phloem and even the xylem of the scale 
traces. In other species of Agathis they also invade the axial bundles. 
5. The two male elements are cells, somewhat unequal in size, limited 
by delicate walls. The nucleus equals in size that of the egg. 
6. The fusion nucleus maintains a central position in the archegonium, 
and five or six consecutive free nuclear divisions ensue. 
7. The mature proembryo is complex. Of its three tiers the median 
is the embryo proper, the upper forms suspensors, and the lower is an 
elaborate penetrative and protective cap. 
8. The cone scale of Agathis is double in nature, homologous with the 
bract and megasporophyll of the Abietineae. Exactly parallel fusion and 
reduction have taken place in the Taxodineae. 
9. The morphology of the gametophyte, of the embryo, and of the 
ovulate strobiliis bespeaks strong specialization. 
10. The Araucarineae represent a highly specialized divergent branch 
of the Coniferales. Those features which at first glance seem to relate them 
to more primitive Gymnosperms are the resnlt of specialization and reduc- 
tion. 
11. The two genera, Araucaria and Agathis , are closely related; 
Agathis is probably the more recent, and within the genus A. australis the 
highest type. 
Methods. 
In preparing the ovules both sides were cut off, the embryo-sac being 
freely exposed or sectioned. A chrom-acetic solution — i-o per cent, 
chromic acid and o-8 per cent, acetic acid — was used as a killing and 
fixing agent. This was allowed to act at least twenty-four hours, and even 
three to five days in some cases. The long immersions produced equally 
