Stopes . — A New Arancarioxylon from New Zealand. 345 
tracheides as is evident to the eye of the observer. Text-fig. 1 perhaps 
gives a fairer idea of the appearance of the woody tissues. These cells 
show up particularly well where the summer wood is just a little crushed, 
as in Photo 3, where, outlining the slightly wavy rays, the blackened and 
relatively uncrushed resin-containing tracheides on either side of them show 
up distinctly. This is enlarged in Photo 4. The deposit of ‘ resin 5 collects 
in the form of large discs or ‘ spools 5 opposite the middle of the medullary 
rays, the lateral extensions of these discs running up and down the contain- 
ing cell-wall for some distance (see Text -figs. 2 and 3 and Photos 5, 6, 
7, and 8). As a consequence of the great quantity of this deposit there 
is a black, wing-like mass on either side of the medullary rays, as seen in 
• a low-power view of the tangential section (see Photo 7), which gives the 
wood an unusual appearance. The rays are also rendered very conspicuous 
in radial section (see Photo 8). 
The extent of this phenomenon seems to be greater in this fossil than 
in any other described form. 
Some mention of such an appearance on a lesser scale has been made 
by Penhallow (’ 07 ), Lignier (’ 07 ) and Jeffrey (T 2 ), but without great emphasis 
or much illustration. I had nearly finished my work on this new fossil, 
and concluded that it was very exceptional in the extent of its ‘ resin- 
spool’ tracheides, when Professor Thomsons (T 3 ) paper reached me. He 
gives, for the first time, adequate treatment and illustration to this peculiar 
feature ; and as his work has largely forestalled what I had to say on the 
subject, I cannot do better than refer the reader to his paper, pp. 23-28, 
as I agree with his conclusions. The present fossil, however, seems to 
show this character even more markedly than the plants he mentions, 
so that its description appears justified and may help to draw attention to 
an interesting feature in the evolution of resin-containing tissue which has 
been considerably overlooked. 
In 1907 Penhallow (pp. 53-58, Text-figs. 4-7) described the wood 
of living Araucarians as showing ‘ more or less numerous elements contain- 
ing resin * which may be scattered, but are more commonly in rows next 
the medullary rays. He said : ‘ The walls of the tracheides may be much 
thicker just opposite the ray where the resin plate comes,’ and he thought 
that in Dammar a and Araucaria these resinous tracheides may be of specific 
value. Lignier (’ 07 , PI. XVII, Fig. 2), from his new species Cormaraucari- 
oxylon crasseradiatum , gives an outline drawing of a portion of a medullary 
ray with specially thickened tracheides on either side. Regarding Lignier’s 
and Penhallow’s interpretation of these tracheides as having a thickened 
wall, Jeffrey (T 2 , p. 538) says: ‘Lignier has described the thickening up 
of the tracheides adjacent to the rays in certain Araucarian woods from the 
French Jurassic. ' It seems entirely probable that he has mistaken resin - 
filled tracheides for thick-walled ones.’ Jeffrey continues, saying that his 
