24 Eames . — The Morphology of Agcithis australis. 
graphical distribution of the species corresponds to the grouping suggested 
above: Groups I and II are Australasian, Group III South American. 
A. Bidwillii is the only species, so far as known, that falls within 
Group I. Text-figs. 1-15 demonstrate the course of the bundles supplying 
the cone-scale. (Note. — All references to figures below are to text-figures, 
unless otherwise stated.) Fig. 1, a tangential section of a portion of the 
xylem of the cone-axis, shows the mode of origin of the two strands. The 
lower, vertically elongated bundle is that of the bract ; above, on either side 
of the gap in the cylinder caused by the exit of this trace, are the two 
bundles which by immediate union form the primary strand of the upper 
series. Worsdell (19) has noted this double origin of the vascular supply, 
and like the writer considers it strong evidence for the double nature of the 
araucarian sporophyll. However, he states that both the bundles are of 
compound origin. With this the writer cannot agree. The method of 
derivation of the bract and megasporophyll in A. Bidwillii is exactly that 
found in the Abietineae. Compare Figs. 75 and 76. Continuing with A. 
Bidzuillii , Figs. 2, 3, and 4 follow these two primary strands in their early 
course. The upper is at first the stronger, but the lower rapidly surpasses 
it in size. Figs. 5, 6, 7, and 8 show the divisions that occur while still within 
the cortex of the cone. Each forms a strong series. After they pass into 
the free scale, the upper is forced downward in the centre by the embedded 
ovule (Figs. 9 and 10). A median group of small bundles is definitely set 
off as ovular supply. Figs. 11-15 — on a much reduced scale — show the later 
course taken by the bundles. Those below the ovule disappear in the 
chalazal region. The rest of the upper series, portions of which have passed 
along the sides of the ovule as crowded twisted groups, come together 
behind the ovule in a horizontal series and pass on into the free ligule as 
strong bundles. The lower group continues its straight course to the end 
of the structure. Thus we have a vascular supply clearly abietinean — two 
series of bundles, arising separately from the axial strands of the cone, and 
completely free from each other throughout. The upper, of double origin, 
supplies the ovules and the upper section of the scale ; the lower furnishes 
the stout lower section, differing from that of the ordinary bract only in its 
great development. Fusion has not affected the vascular tissues in any 
way, and the megasporophyll, though smaller than the huge bract, is free 
therefrom to a considerable extent, and its bundles have not been reduced. 
To the second group belong Araucaida excels R. Br., 1 A. Ciinninghamii , 
Sweet., A. Rulei , F. Muell, and A. Cookii , R. Br. Among these species the 
ligule is short and small, with a very weak vascular supply, or none at all. 
Though in the various species the details of the bundle- course are rather 
1 The anatomy of the cone scale in the cases of A. excelsa and A. brasiliana is as given by 
Radais (9), Strasburger (12), and Worsdell ( 19 ); in all other cases the writer has made his own 
studies. 
