JKFFUKY. — .VU.VrC.VHlOXVLOX TYI'i:. 533 



•svith the trabeculae of Sanio, linniHeil j)rocesses, crossing the lumen 

 of the tracheids, common to the Gnetales, Coniferalcs and a few 

 Anji;iosperms. Another feature of the Araucarioxylon type is the 

 usual absence of wooil parenchyma and the smooth walled character 

 of the ray cells. The last two features are less typical than the ones 

 mentioned above since they are shared to a considerable extent by 

 the woods of the remaining tribes of Coniferalcs. The last character 

 has had recently assigned to it an apparently exaggerated importance.^ 

 Gothan has recently rcfcrrtnl woods, which are strikingly Araucarian 

 in the aggregate of their characteristics, to abietincous adinities on 

 account of their strongly pitted rays, apparently losing sight of the 

 fact that pitted rays occur commonly or sporadically in all the tribes 

 of Conifers. The present article is to be devoted to the historical, 

 comparative anatomical and experimental study of the rays and wood 

 parencliyma in the Araucarian Conifers. 



Beginning with the historical aspect, Figure a, Plate 1, shows the 

 character of the pitting in the tracheids in an Araucarian wood of 

 the Upper Jurassic, to be described in detail on another occasion. 

 The pits are numerous and in several rows, with the marked alterna 

 tion, characteristic of the Araucarioxylon type. They are not how- 

 ever as closely approximaterl as is the case with the pits in the tracheids 

 of the adult wood of the living genera Araucaria and Agathis. Figure 

 h, Plate 1, illustrates the ray structure in the same wood. It is clear 

 that the cells of the ray, in contact with one another are very strongly 

 pitted, exactly for example as is commonly the case in the rays of the 

 Al)ictineae. On account of the pitting of the ra^'s in woods of this 

 type from the Upper Jurassic of King Carl's Land ^ and of the island 

 of Spitzbergen* Gothan has recently referred them to abietincous 

 affinities. It is to be pointed out in this connection that Seward has 

 considered woods of a similar type from the Upper Lias of Yorkshire 

 in England ^ to belong to the Araucarian conifers. Moreover Lignier 

 more recently has described woods of a similar or nearly similar 

 horizon, as likewise of Araucarian affinities.^ About the same time 



2 Gothan, Zur Anatomic Icbender u. fossiler Gymnospormen-Hoelzer; 

 Abh. d. Koenig. Preuss. goolog. LundcsanstuU ; Neuc Folge, Ileft 44, IJerlin 

 (1903). 



3 Gotlian, Fossilen Hoelzcr von Kocnig Karl's Land, Kung Svcnsk. Veten- 

 skap. Handlingar, Bd. 42, Xo. 10. 



4 Gothan, Fossilen Holzrcsto von Spitzbergen, Kung. Svcnsk. Handlingar, 

 Bd. 4.5, No. 8. 



5 Cat. of Mcsozoic Plant, Brit. Museum, Jura.ssic Flora, Pt. 2, pp. 56, 57, 

 pis. 6, 7, London (1904). 



6 O. I.ignior, W'getaux Fossiles dc Xormandie, IV. Bois Divers (Ire. 

 Serie), Caen (1907). 



