26 E antes . — The Morphology of A gat his australis. 
bundle is yet within the cortex of the cone, the two series are formed. The 
upper is entirely given over to supply the ovule. It consists of a series of 
four to six bundles, all of which pass beneath the ovule and enter its base. 
The lateral portions of the series, so prominent in A. Bidwillii , which pass 
on into the scale have entirely disappeared. Beyond the ovule no upper 
series is visible, and the ligule has no supply. The lower series is normal. 
A. Cookii from this group is also figured to show features transitional 
to Group I. An upper series is formed from the single normally oriented 
bundle, as in A. Cunninghamii (Figs. 24-8). As in A. Bidwillii , only the 
central portion of this becomes ovular supply. The lateral portions continue 
beyond the ovtde into the distal part of the scale (Fig. 30)— a more primitive 
state than in A. Cunninghamii — but do not reach the ligule as in A. 
Bidwillii. A. Ridei closely resembles the former species in this respect : 
a weak series of upper bundles is formed, some of which tend to be lateral, 
but all enter the ovule. The inverted series in A. excelsa , which consists of 
a few small bundles, dies out midway beneath the ovule, and the ovular 
supply is derived entirely from lateral bundles of the lower series. 
The third group consists of A. brasiliana , A. Rich, and A. imbricata , 
Pav. Flere no upper series at all is formed, and the ovular supply is derived 
from the lower series very near the base of the ovule, passing directly in. 
See figures of A. brasiliana , Nos. 32-8. This species represents the 
greatest reduction in the genus. A. imbricata is closely similar. Even 
external evidence of the ligule has almost disappeared. 
Thus the genus Araucaria itself presents a type of cone scale — that of 
Group III — the vascular supply of which is very greatly simplified. And it 
displays the method and steps of this reduction from a type distinctly 
abietinean, at least in the origin of its supply. 
Further comparisons emphasize the mode of origin of the cone scale of 
Agathis. It has been stated above that the genus Athrotaxis displays 
stages of fusion and reduction of importance in this respect. Figs. 39-59 
illustrate this. The longitudinal sections (Figs. 82-4) show the external 
features and the general plan of the bundle system. A. ctipressoides 
(Fig. 82) has a prominent fertile scale which in its expansion has nearly 
absorbed the bract, the latter projecting as a tiny tongue from the tissue of 
the former. In A. laxifolia (Fig. 83) the two members are about equally 
developed, the scale resting upon the well-developed bract as a large 
cushion with rounded end — a very blunt ligule. In the third species, 
A. selaginoides (Fig. 84), all external evidence of a scale has disappeared, 
the fertile structure having a ventral surface as free of outgrowths as that 
of Agathis or Saxegothaea. The change in the bundle systems takes place 
pari passu with that of the external structures. Transverse serial sections 
demonstrate this. The vascular supply in A. cupressoides leaves the stele 
of the cone as a cylinder (Fig. 39). The latter breaks up immediately on 
