74 Torrey. — Telephragmoxylon and the 
just mentioned : namely, that wood parenchyma arose by the septation of 
tracheides at the end of the annual ring. Two species of the wood have 
been recognized. The following description is based upon T. brachy- 
phylloides . 
From an examination of the microtome sections, the first and most 
obvious fact is that we are dealing with a wood belonging to the Araucarian 
complex which dominated the Mesozoic forest. The bordered pits on the 
tracheides are uniseriate and are commonly tightly pressed against one 
another, though on larger tracheides biseriate alternation is not uncommon. 
The pit mouths are elongate and oval. 
The rays are manifestly Araucarian ; in tangential aspect they show 
themselves as either uniseriate or biseriate. Their cgIIs show a slight 
gummy inclusion. The lateral tracheide field (as seen radially) is impressed 
with few to ten small pits which have either oval or circular openings. 
These Araucarian features are well shown in Fig. i, PI. III. Traumatic 
vertical resin-canals are present — a fact very suggestive of the phylogeny of 
the Araucarians, but one with which we are not now concerned. They are 
shown in Fig. 2, PI. III. The wood at this point is poorly preserved, but it 
came from the same blocks that have exhibited the feature which makes the 
wood distinctive. 
In sections inclined slightly from the true tangential plane towards the 
transverse, so that summer as well as spring wood may be included, there is 
manifest in many of the terminal tracheides of the annual ring successive and 
apparently double diaphragms which cross their lumina. These diaphragms 
are the end walls of short tracheides whence the middle lame] la has 
disappeared. Each bears from one to three bordered pits. In other words, 
we are dealing with a condition of initial septation of the tracheides at the 
terminus of the annual ring : hence the generic name Telephragmoxylon . 
That these plates and their pits are very abundant and definite is evidenced 
by our microphotographs. 
In Fig. 3, PI. Ill, is seen a cross-section of the wood. Stretching 
obliquely across the field is a darker band of tracheides. The darker colour 
is due to the fact that a lucky section has cut at least five successive 
tracheides at such a point that their cross-diaphragms are visible. On one 
of these septa a pair of bordered pits is seen, and evidence of the same is 
visible on three others. 
In Fig. 4, PI. Ill, of a tangential section, an oblique band of septated 
tracheides runs across the field. Even with the low magnification employed 
it is evident that bordered pits are present in the septa. Fig. 5, PI. Ill, 
shows a detail of these same tracheides under higher magnification. 
In Text-fig. 1 is shown a stereogram reconstruction of a small block of 
Telephragmoxylon wood. In Text-fig. 2 we have a similar figure of the 
allied genus Brachyoxylon. 1 he essential difference is obvious. 
