33 
Eames . — The Morphology of Agathis australis. 
Cunninghamia , and further, another genus, A thro taxis , containing both an 
‘ aplosporophyllous 1 and a ‘ diplosporophyllous ’ species. Such fundamental 
differences could hardly occur even within a natural family, much less 
within the limits of a genus. In the Araucarineae, a so-called ‘ aplosporo- 
phyllous ’ tribe, one species, Araucaria Bidwillii , is found, the ‘ diplosporo- 
phyllous ’ nature of which can hardly be questioned. Even in Agathis 
itself there remains a species possessing a cone scale with a double series of 
bundles. Further, Hollick and Jeffrey (3) have demonstrated a double 
series of bundles in the cone scales of Mesozoic Araucarians. Apparently 
the strobili of the Conifers are strictly homologous, and hence the terms 
‘aplo-’ and ‘ diplosporophyllous’ may appropriately be abandoned. 
Much of the evidence on which the conclusion was drawn that the 
fertile structure in the Araucarians and the Podocarps is of simple nature, 
is related to the orientation of the ovular supply. Thomson (17) has 
announced that in some Abietineae the ovular supply is inversely oriented, 
thus a double inversion occurring in the ovuliferous scale. The conclusion 
is then drawn that, since in Saxegothaea and Microcachrys the inverted 
series is very weak, and supplies only the ovules, it is merely ovular supply. 
This must likewise apply to the Araucarineae. Hence the sporophyll in 
these forms must be simple. But under these conditions so would be those 
of Cunninghamia , Athrotaxis laxifolia , and A. selaginoides , which certainly 
are not of a simple nature. In such cases as Saxegothaea , Agathis , Cunning - 
hamia , Microcachrys , and the two above-named species of Athrotaxis , the 
upper series is not merely ovular supply morphologically, though that may 
be chiefly its physiological function. Naturally the extreme distal portions 
are, however. These bundles are the last vestige of the upper series, retained 
to supply the ovules. There is clear evidence of this. These supposedly 
strictly ovular supply bundles in Agathis australis and A. vitiensis give off, 
as they turn into the ovule base, branches which continue the course of the 
original bundle — a scale supply branch. Further, strands departing to 
ovules in forms where the upper series is not reduced are not freed until the 
immediate vicinity of their destination is reached. Why, even if the sporo- 
phyll is simple, should an ovular supply be set off far back at the base of 
the cone scale as in Saxegothaea and Cunninghamia , or part way out in the 
scale as in Agathis and Athrotaxis selaginoides ? Athrotaxis cupressoides 
(Fig. 8a) suggests the normal point of origin and short course of ovular 
bundles in that genus. Compare with A. selaginoides (Fig. 84). In Arau- 
caria brasiliana , where fusion has undoubtedly gone even farther than in 
Agathis , the ovular supply is derived almost directly beneath the base of 
the ovule (Figs. 35 and 36 ). Finally, the ovular supply bundle is not 
generally inverted. Compare the statements of Radais (9), Van Tieghem 
(18), and Strasburger (13). It may be oriented normally or laterally, but 
is most frequently concentric. The orientation may change during the 
