1gt5] AASE—MEGASPOROPHYLLS OF CONIFERS 281 
The Abietineae and Podocarpineae have come from a common 
primitive stock. The Abietineae are more advanced in the develop- 
ment of the scale, but more primitive in holding on to a perfect 
cone. “The evidence at present is much in favor of the lycopodean 
ancestry of the conifers.’”’ He has little faith in the brachyblast 
theory, as it depends for its support mostly on abnormalities and 
the vascular anatomy of the cone scales. ‘But abnormalities, 
~ especially when they are supposed to be more or less of the nature 
of reversions, afford by themselves unsatisfactory evidence of phy- 
logeny.”’ Vascular anatomy disproves the double nature of the 
megasporophyll of the araucarians and podocarps, except in some 
species in the latter, and there the compound structure is of recent 
origin. 
Srynort (4) in 1913 gave a very clear account of the strobilar 
anatomy in a number of podocarps. He is of the opinion that the 
podocarps and araucarians, along somewhat parallel lines of 
development, have been evolved from ancient abietinean stock. 
The scale in the Abietineae, the ligule in the araucarians, and the 
epimatium in the podocarps are all homologous and vestiges of an 
axillary shoot, and a simple sporophyll has arisen either by the 
fusion of both of its parts or by the abortion of one. Of the podo- 
carps he considers those most primitive in which the epimatium is 
well developed and has a strong vascular supply, as Podocarpus; 
and those most advanced in which there is a reduced epimatium, 
as Dacrydium. In Podocarpus dacrydiodes there is a definite step 
in the direction of Saxegothaea, Microcachrys, and Pherosphaera. 
The resemblance in reproductive structures between certain mem- 
bers of the Podocarpineae and Cephalotaxus, the most primitive 
genus of the Taxineae, suggests that the latter family has arisen 
from some ancient member of the Podocarpineae. 
Eames (1) in 1913, in a paper on Agathis, considered also the 
megasporophyll situation in other conifer groups and concludes 
that the megasporophyll is compound in origin in all Coniferales. 
“Even within themselves the Araucarineae show a complete series 
from a form with strobilar units of a distinctly double nature to 
one most simple through reduction.” EAMEs has traced a similar 
reduction in the Taxodineae. 
