JEFFREY. — ARArCARIOXYLOX TYPE. 537 



found by (lotliaii in certain araiu arian \voocls from King ("arl'.s Land 



apparently wrongly referred hy him to ahietineous affinitie.s.^ I'Mgure 



r, Plate 3, is a longitudinal section of the same species, illustrating 



the vertical distribution of the wood parenchyma. Seldom or never 



does parenchyma make its appearance in the normal wood of outer 



annual rings. At this point it is convenient to record another feature 



of interest. Througli the kindness of Messrs. Eames and Sinnott, 



Sheldon fellows of Har\ard University, who have recently spent a 



year in the investigation of the coniferous flora of the Australasian 



region, the writer has been supplied with seedlings of the genera 



Agathis and Araucaria. It was found on investigation that in the 



case of Agathis there was usually no wood parenchyma in the first 



annual ring in the seedling until it had reached a considerable size. 



In fact it is only in the vigorous branches that bear cones that the 



parenchymatous elements appear in any abundance. The recapitu- 



lationary phenomena in the case of wood parenchyma are accordingly 



dela\eil until the plant has reached a certain vigor, thus presenting 



an exact homologue with the conditions found for example in certain of 



the Abietineae, which are normally without resin canals in the wood ^ 



and in Sequoia giganica}'^ Here the resin canals, so characteristic of 



the pine-like Abietineae, occur in the first annual ring of vigorous 



vegetative shoots and in a few cases only in the axis of the cone. The 



evidence in the case of the genus Sequoia and in the Abieteae, has been 



accepted by other investigators who have given special attention to 



the Conifers, as a clear indication that both the Abieteae and Sequoia 



have come from pine-like ancestors. -^^ Mr. Thomson's views in this 



respect are particularly significant as his attitude in regard to the 



affinity of the Araucarian conifers is diametrically opposed to that of 



the present writer. As will be pointed out later, the admission of the 



validity of certain general principles in the case of certain coniferous 



tribes, logically implies their application to the whole series. We find 



then this feature of accord between recapitulationary phenomena in 



for example Abies and Sequoia on the one hand and Agathis on the 



8 Gothan, Die Fossilen Hoelzor von Kociiig Karl's Land, I\uiif>;. Svensk, 

 Votonskah. Handlingar, Bd. 42, No. 10. 



9 JefTrov, Comp. Anat. of tho Conifcrales, No. 2. The Al)ictiiicao, Mem. 

 Boston Soc. Nat. Hi.st., 6, pp. i-37, pis. 1-7 (1904). 



10 Comp. Anat. Coniferales, No. 1, Tlio Genus Sequoia, Mem. Best. Soc. 

 Nat. Hi.st., 5 (UXW). 



11 Coulter and Chamberlain, Morphology of Gymno.sperms, Chicago 

 (1911), and Thomson, R. B., Mcgasporopliyll of Saxcgotlica and Microcachrys, 

 Bot. Gazette, 47 (1909). 



