66 
Sinnott . — The M orphology of the 
The earliest accounts of vascular anatomy in the female cone of 
Conifers are in general more clear and comprehensive than those published 
more recently. Van Tieghem ( 19 ), in 1869, investigated the ‘ female flower’ 
in everything from Cycadales to Gnetales, and was the first to apply 
anatomical criteria to the question of the morphology of the ovuliferous 
scale. Strasburger, in a number of his works, notably ‘ Angiospermen 
und Gymnospermen ’ and ‘ Coniferen und Gnetaceen ’, extended and ampli- 
fied Van Tieghem’s observations. A notable paper by Radais ( 9 ), and one 
which for some unaccountable reason seems to have escaped entirely the 
attention of subsequent writers on the subject, gives a clear account of some 
very careful and extensive investigations on the anatomy of the female cone, 
both young and mature, among the Abietineae, Taxodineae, and certain 
Araucarineae. The results obtained by these writers agree in emphasizing 
the fundamental similarity of the vascular supply to the strobilar appendage 
among all living Gymnosperms above the Cycadales. In every case the 
sterile leaf or bract subtends an axillary structure which is sometimes 
fused entirely with the bract, and is often much reduced, and which bears 
the ovule or ovules. This double appendage (leaf and scale) is supplied by 
a double vascular system from the central cylinder of the axis. 
In Ginkgo a normal double foliar strand departs from the stele and passes 
into the subtending leaf. From each side of the gap thus caused springs 
a bundle, and these two, each of which soon bifurcates, enter the mega- 
sporophyll or axillary ovuliferous stalk, which is thus obviously a branch 
provided with a vascular cylinder of four bundles. 
In the Abietineae (Diagram 8, a) conditions are very similar save that 
the subtending structure is a bract, not a foliage leaf, and that the axillary 
ovuliferous scale is not so evidently a branch. A strand precisely resem- 
bling the foliar bundle supplies the sterile bract. After its departure two 
bundles arise from the cylinder, one from each side of the gap, and approach 
each other by their adaxial ends, xylem outside and phloem inside, thus 
assuming an orientation which is inverse to that of the bract supply. The 
latter passes without division into the free bract, but the two scale bundles 
during their course through the cortex fuse into an arc or partial cylinder, 
which divides later into three parts. The small median bundle undergoes 
no further branching, but the two large lateral ones each give off a strand 
to an ovule and then by repeated division form the wide vascular arc which 
enters the lamina of the scale. The cone scale is thus precisely like an 
axillary branch in the origin of its vascular supply. A striking similarity 
is evident between the strobilar anatomy of the Abietineae and that of 
Podocarpus (Diagram 8, A and B). 
In the Taxodineae and Cupressineae the bract and scale are more 
or less completely fused with one another, but where the latter is dominant, 
as in Sequoia , the vascular supply is double at its origin, and consists 
