Stiles . — The Podocarpeae . 
475 
reveals two layers, the outer soft semi-fleshy layer (formed from the 
epimatium) and the inner woody layer (formed from the integument). By 
the time the seed contains a young embryo the outer layers of the integu- 
ment are already becoming thickened and lignified, and are clearly 
differentiated from the epimatium. The inner layers remain thin and 
parenchymatous. The thickening and lignification appear to commence at 
the micropylar end, the chalazal region being the last to become lignified. 
The vascular system of the ovulate structure of Podocarpus nagi appears 
to be more complicated than that previously described for the ovule of any 
Conifer. The sporophyll con- 
tains a row of four or five 
bundles, and is thus parallel 
veined like the foliage leaves. 
The ovular supply at the base 
of the ovular stalk consists of 
a row of three or four bundles 
(Text-fig. 7, a) having their 
xylem and phloem orientated 
inversely as compared with 
the sporophyll bundles. These 
bundles ascend towards the 
chalaza on the sporophyll 
side of the ovule, although 
they may sometimes be la- 
terally displaced. As in P. 
macrophyllus , one of the two 
middle bundles if there are 
four present, or the median 
one if there are three, ascends 
to the chalaza, and bending over the top of the ovule descends on the other 
side towards the micropyle. As in P. macrophyllus and P. spinulosus , 
this bundle divides into two after passing over the top of the ovule, although 
one of the two may soon die out. However, whereas in the species of 
Eupodocarpus cited the median ascending bundle does not divide between 
the stalk and the chalaza, in P . nagi it may do so. Thus in Text-fig. 7, c, 
the bundles marked B 2 , B 3 , B 4 , have all arisen by division of B. The 
bundles lateral to the main bundle which passes over the chalazal end of the 
ovule bend round the side of the ovule as in P. macrophyllus , and descend 
towards the micropyle. Thus in the series shown the bundles A, B 3> c, and 
D, bend round at various levels and descend towards the micropyle ; in 
this part of their course they are marked a , b 3 , c , and d (Text-fig. 7, c, d). 
As in P. macrophyllus , these descending bundles may divide. They descend 
aimost to the micropylar region (Text-fig. 7, b), and in this respect differ 
Text-fig. 6. Diagrammatic representation of a 
transverse section through an ovule of Podocarpus nagi , 
showing the distribution of canals. The dotted line marks 
the outer limit of the integument, x 8. 
