CRETACEOUS CONIFERALES 59 
shows the margin of a healed wound in 4gathis alba (Rumph.) 
Salisb., from material derived from the Botanical Garden at Buiten- 
zorg, Java. There is a considerable amount of callus parenchyma 
on the right of the figure and some of the tracheids adjacent to this 
are blocked with mucilage. To the left of the wound-callus the 
tracheary tissue presents a normal appearance. This condition is 
to be contrasted with the state of affairs found in the Brachyoxylon 
type of wood, as represented in our fig. 2, Pl. 14, which shows a 
row of traumatic resin canals running from the callused margin 
of a healing wound. We have found that Brachyoxylon presents 
this marked contrast to Araucarioxylon, viz., that whereas traumatic 
resin canals are characteristically formed as the result of wounding 
in the former, they are invariably absent in the latter. That a 
similar contrast occurs in our Araucarioxylon is clearly shown in our 
fig. 3, Pl. 21, which represents a transverse section of the wood, 
Xx 40, and shows the margin of a healed wound in this species, for 
there is the same absence of traumatic resin canals which is found 
to be characteristic of the living genera: Agathis and Araucaria. 
We have made a large number of observations on this point and feel 
that the above general statement as to the absence of traumatic resin 
canals holds as strictly in the case of our fossil as it does in the case 
of the genera last mentioned. Figure 5, Pl. 21, shows a longitudinal 
radial section of the wood of our Araucarioxylon, X 180. The 
preservation is not good and this, together with the presence of 
mucilage on the tracheids, somewhat obscures the structural fea- 
tures. It may be noticed that the pitting is strictly of the type found 
in Agathis and the large-leaved Araucarias of the section Colymbea, 
for the bordered areas are for the most part in several rows per 
tracheid and are uniformly alternate. We have found the condition 
of alternation or mutual flattening to be universal in this wood, just as 
it is in Araucaria and Agathis. Figure 6, Pl. 21, shows another radial 
section under the same magnification, which elucidates the structure 
of the resiniferous elements. One of these is shown in the middle 
of the field, which is crossed by a transverse septum. The resin cells 
in our species are of the nature of resiniferous parenchyma similar 
to that found in Cupressinoxylon Goepp. and present a contrast to the 
resiniferous tracheids which are found in 4gathis australis (Lamb) 
Salisb. 'They resemble, however, similar parenchymatous resinif- 
