No. 520] 



NOTES AND LITERATURE 



253 



RECENT INVESTIGATIONS ON THE COMPARATIVE 

 ANATOMY OF CONIFERS 



Until quite recently there has been an increasing tendency to 

 regard the two important coniferous tribes which are, at the 

 present epoch, respectively characteristic of the northern and 

 southern hemispheres, viz., the Abietinerc and Araucarinere, as 

 of different origin and not nearly allied with one another. This 

 view of their derivation is, for example, represented by Professor 

 Seward in his monograph on the Araucarineae 1 and by Professor 

 Penhallow in his "Manual of North American Gymnosperms. " 2 

 A similar opinion has even quite recently been expressed by Mr. 

 Thomson. 3 While the inferences of those whose conclusions are 

 based almost entirely on a consideration of the structure of ex- 

 isting representatives of the Coniferales and of their surmised 

 ancestors from the Paleozoic, have had the marked separatist 

 trend indicated above, of late quite another tendency has made 

 itself felt as a consequence of the structural investigation of the 

 Mesozoic conifers and a comparison of these with existing tribes. 



An important contribution on the structure of the Jurassic 

 woods of King Karls Land 4 contains an account of a ligneous 

 species, which the author names Cedroxylon transient. This 

 species is remarkable for the fact that it at the same time mani- 

 fests the ray structure of the Abietineae and in many instances 

 the characteristic alternating radial pitting of the tracheids, 

 which is a feature of the wood in existing Araucarineae. On 

 account of the latter feature Gothan, while referring the wood 

 to the abietineous genus Cedroxylon Kraus, applies the specific 

 appellation transiem, to indicate that in his opinion the wood in 

 question marks a transition from the Abietineae to the Aura- 

 carinesB. Of the general soundness of this view there can be no 

 question. Nearly contemporaneously Jeffrey published an ac- 

 count of another Mesozoic wood presenting the same structural 

 peculiarities as Cedroxylon transient;, together with the added 

 abietineous feature of the possession of short or spur shoots, re- 



The Araucarineae, Eecent and Extinct," Phil. Trans. Boy. Soc. 

 London, 1906. 



a Ginn & Co., Boston, 1907. 



The Megasporophyll of Saxgothea and Microcachrys," Bot. Gazette, 

 47, May, 1909. 



Svcntl: V'tmzlap. ITandUngar, 42, No. 10. 



