1915] BURLINGAME—ARAUCARIANS 97 
the root and shoot of both Agathis and Araucaria, in the early 
wood of seedlings, in the wood of the cones, and may be traumati- 
cally recalled in the older wood of both root and shoot. Further- 
more, it is present in the more abietinean Araucarioxyla of the 
Cretaceous. (2) “‘They likewise had strongly pitted rays.’’ This 
is shown by their presence in the inner portion of the cone axis of 
living forms and in the normal wood of those cretaceous forms 
(Araucariopitys, for example) which the author assigns to the 
Araucarineae. Pitted rays may also be recalled in the seedling 
and root by injury. (3) “‘The possession of these two features is 
quite inconsistent with their derivation from cordaitean ancestry,”’ 
notwithstanding the practical identity of structure of the two 
groups. This argument rests partly on recapitulationary phe- 
nomena and partly on merely calling the transitional cretaceous 
conifers araucarians rather than abietineans, which some of them 
resemble far more closely. 
The second part deals with ‘“‘the characteristic features of the 
tracheids and the nature of the pitting.’”” The conclusions are: 
(1) ‘The characteristic pitting of the wood of Agathis and Arau- 
caria, the Araucarioxylon type, is not ancestral but more recently 
acquired.” This conclusion is based on the fact that the multi- 
seriate, flattened, and appressed pits of the mature wood of living 
araucarians and of Cordaitales is replaced in the inner woed of the 
cone and seedling axis of living genera and in the innermost wood 
of the stem of mesozoic forms by a type of pitting with the pits less 
frequently multiseriate, flattened, or appressed, but often uniseriate, 
remote, and round. (2) Since bars of Sanio are absent from the 
mature wood of living genera (see THoMsON 70 for a contrary 
opinion) and from the wood of mesozoic Araucarioxyla, but are 
present in the wood of the cones, it follows that they are a feature 
of the ancestors of the Araucarineae. In anticipation of objections 
to be urged later, it may be mentioned here that the author admits 
their absence in the stem of the mesozoic forms, in the seedling, 
and probably in the leaf trace, in all of which they should be found 
in accordance with theoretical expectations. (3) ‘‘On the basis of 
comparative studies of the tracheids of the Araucarineae they cannot 
be regarded as primitive representatives of the coniferous order.” 
