No. 520] NOTES AND LITERATURE 



255 



the ancestral Abietinea 1 , which lie names Paraa droxylon, on 

 account of its general resemblance to the abietineons wood genus 

 C< ilrn.n/lon Kraus. 



In an important though brief article on the occurrence of the 

 "hars of Sanio" in recent and extinct coniferous woods, Miss 

 Gerry 8 comes to the interesting conclusion that the presence of 

 this structural feature, consisting of transverse bands of cellulose 

 interposed between the radial pits of the tracheids of the wood, 

 is characteristic of all conifers, except ihc Araucarinem. Her 

 results are of special significance in connection with the conclu- 

 sions reached by Jeffrey and Hollick, cited above, in regard to 

 the true affinities of the supposed Sequoias. Thuyas, etc., of the 

 Mesozoic. On the basis of the absence of the hars of Sanio in 

 well-preserved woods of supposed Cretaceous Sequoias, etc., she 

 arrives at the result that these are in reality of araucarian affini- 

 ties, as was inferred by the authors just mentioned, as the conse- 

 quence of the combined structural study of the branches, leaves 

 and cone-scales of the conifers in question. 



The general result of all the investigations cited in the fore- 

 going paragraphs is to show that there existed during the Meso- 

 zoic conifers, which were clearly transitional between the abieti- 

 neous and arauearineous types of the present day. The pre- 

 dominance of the testimony moreover in favor of the Abietineae 

 rather than the Araucarinea? having been the older coniferous 

 tribe is apparent. Recently Jeffrey has brought forward very 

 definite positive evidence in favor of this view, based on the 

 structure of Mesozoic pines. 9 Known structurally heretofore 

 only as to their wood, the pines of the Cretaceous, which are not 

 without closely allied relatives in the earlier Mesozoic, are here 

 described in relations to the very important features of leaf 

 structure. Among the abietineons remains the most siirnifiYant 

 because the most archaic genus is Pirpinus Jeffrey, which has a 

 detailed resemblance in foliar organization to certain Cordaitales 

 of the Paleozoic, as well as the centripetally formed primary 

 wood which is the common possession of the Pteridophyta and 



