ti'E.MiAi.i.uw] Noin'll AMKKICAN Sl'KClKS or DAPOX YL< >N B7 



most iiiiporliuit (liii^'iii)stie iVaturo. 01' tlie uiglilLnjii siK-cies uow en- 

 titled to reco^Miitioii, lliree slimv more or less cU-arly dcliiied growth 

 rings while in tlit' renniiniiig lit'teeii. they are ol>»ciire or obsolete. It 

 theirefore appears that there are lifteeu species of L'ordaites which con- 

 form to the general type oi' Araiicaria, while tluve cont'orm to the type 

 oi' JJanimara. Tliij is in strict harmony with t.iie generally accepted 

 view that these phints are oi' distinctly Araucarian alllnities but without 

 implying actual connoctioii. inasmuch, however, as the growth rings 

 are initiated by alternating growth and rest jKiriods wiiieh are in turn 

 determined ciiielly iiy tlimatic cnn<liliniis, such structural variations are 

 not necessarily indications oi relationsiiip, and their chici ini]»orlanre 

 imiy lie in their indication oi varying clinuitic conditions as o])erating 

 upon dilicrent species oi the same genus. lnier[)reiing these considera- 

 tions in the narrow sense, it would seem as if the genus L'ordaites must 

 Inivi! inchuleil species which tlourishcd under widely dilVcrent climatic 

 comlitions ; hut interpreted in the broader sense of the Araucarieie as 

 a whole, we are to conclude that the genus as uow constitulod, em]>races 

 in reality wliat must eventually prove to be distinct genera of the separ- 

 ate types oi Araucaria and Dammara as parallel examples among existing 

 Araucariea'. 



All ol)servationi agree in the fact ol a comi)lete aljsence oi resin 

 canals such as occur in the AbietineiP on the one hand, and ot si>ecialiscd 

 resin cells such as occur in the (. upressinerj on the other hand, and in 

 this we observe further agreement with the modern Araueariea", but as 

 in the latter, all known species show undoultled evidence of the more 

 or less abundant occurrence oi resin in the medullary rays, and also in 

 the tracheids of the woody cylinder. The principal occuiTcnce of this 

 material, however, is in the pith, where it is deposited in cells (tig. S, 

 r. c.), or. in the bark where it is developed in connection with specialised 

 resin canals (tigs. 2, (>, 7, r. c.) or in .sjiecial cells. In these respect^s there 

 is a somewhat close resenddance to what may be notLti in Araucaria. 



The ]>ordered pits constitute one of the most prominent and char- 

 acteristic structural features of these plants. Some of the species under 

 exanumition show in a somewhat remarkable manner, the gradual trans- 

 formation of the scalarit'(n'ni ■structure into that oi the typically bordered 

 pit, and in no case is this exhibited with greater clearness than in C 

 Brandlingii (figs. 9, 10, 11), whore a properly selected radial section will 

 show all tlie gradations from one extreme to the other. This fact is by 

 no means a new one, since so long ago as 1840, Don pointed out that 

 tracheids of Cycas revoluta would exhibit scalaril'onn structure at one 



