72 Worsdell .— The Structure of the 
in that of Dacrydium and Microcachrys among the Podo- 
carpeae, where the ovular integuments are distinct from each 
other, the ovule is spoken of as ‘ dichlamydeous.’ In Cephalo- 
taxus , Podocarpus, as also in Cycads, where the two integu¬ 
ments (consisting of the inner bony and the outer fleshy one) 
are intimately united, the condition is ‘ holochlamydeous.’ 
In the Araucariaceae, however (including the Abietineae, 
Araucarieae, and Cupressineae) the outer integument of 
the sporangium has assumed a permanently vegetative de¬ 
velopment, and is exactly comparable in this respect to 
the vegetatively-developed outer integument observed and 
described by this author in Hesperis and other plants. 
This outer integument, then, is the seminiferous scale or 
a half of it, as unlike an ordinary outer integument as it 
well could be, but shown to be such by the inversed orienta¬ 
tion of its bundles, characteristic of all outer integuments 
(a fact first discovered by Strasburger in Cephalotaxus\ by 
the fact that without it the sporangium would possess but 
a single integument, and thus offer an incongruous dis¬ 
similarity from the sporangium in the Taxaceae, and, not 
least, by the period of its development, which is always 
(except in Pinus resinosa , Soland) subsequent to that of the 
sporangium, whereas if it were a sporophyll it should be 
developed, naturally, before the sporangium. This dis¬ 
similarity from what obtains in the Taxaceae would again 
be most apparent if the seminiferous scale or its half were 
regarded as a sporophyll or carpel, for no such organ is found 
in the above-named section of the order. 
As regards the homology of the sporangial envelopes with 
structures found amongst Vascular Cryptogams, the inner 
integument corresponds to the indusium of Ferns, Isoetes, &c., 
while the outer integument is the homologue of the ligule in 
Isoetes , Selaginella , &c., a view which is so far identical with 
that of Sachs and Eichler, who regarded the seminiferous 
scale as of ligular nature. 
While in the Abietineae the seminiferous scale very fre¬ 
quently consists of the sporangial representatives of the first 
pair of leaves of the axillary bud fused with that of the a 7 iterior 
