1915] BURLINGAME—ARAUCARIA BRASILIENSIS 31 
taxus) that have suggestive resemblances in other respects to one 
another. 
Eames (8) has laid special stress on the fact that in Agathis 
the fusion nucleus remains in the center of the archegonium and 
that its divisions are limited to a restricted part of the egg cyto- 
plasm. He looks on this as a specialization. I should be inclined 
to minimize the importance of this feature, for in Araucaria division 
occurs wherever the impact of the male cells has left the egg nucleus. 
Neither is the restriction a noticeable feature further than is 
determined by the fact that the proembryonic free nuclei are 
restricted to the limits of the male cytoplasm that envelops them. 
The irregular division in the proembryo, the indefinite number 
of nuclei formed, and the method of their arrangement distinguish 
Araucaria rather sharply from the Abietineae, though some or all 
of these features are paralleled among the other tribes. 
The number of cells in the proembryo before elongation, and 
the time of wall formation vary widely. Abietineae usually, at 
least, have four tiers of four cells each. In the Cupressineae the 
cells are usually fewer and not so regularly arranged. Among the 
Taxaceae the numbers run much higher (18-32) and the arrange- 
ment is still less regular. Walls form somewhere about the 8-celled 
stage in Pinaceae, but at widely different stages among the Taxaceae. 
In all other recorded conifers, excepting Actinostrobus (18a), the 
proembryo is arranged in more or less regular vertical tiers and the 
growth is downward. In the araucarians the embryo is not tiered, 
but concentric at the time walls are formed. It takes on a pseudo- 
tiered appearance later through the elongation of the upper cells 
of the concentric outer layer to form the suspensor and the lower 
ones to form a cap. In this respect the proembyro is unique, 
though Cephalotaxus (12b, 23), Sciadopitys (17), and some species 
of Podocarpus (21) resemble it in having a cap below the embryo 
cells. In neither of these, however, is the embryo group completely 
Surrounded as in the araucarians. These resemblances do not 
contradict a relationship between araucarians and taxads, nor do 
they add very much strength to the evidence for it. The structure 
of the proembryo is so different from that of the Abietineae that 
it is not easy to see how it could have been developed from it. 
