442 BOTANICAL GAZETTE [December 



in the changes which ushered in the Tertiary the crown was almost 

 completely destroyed and that a lower more ancient and overshadowded 

 branchj the Abietineae, became a new ''leader'' and developed luxuri- 

 antly. 



o 



from 



Mesozoic 



lated of late. Reference has been made above to the striking abietine- 

 ous characteristics of the older Araucarians. It has been pointed out 

 that the w^ound-reactions of the older Araucarineae are a strong 

 indication of their abietineous derivation. Further, although the older 

 Araucarians show striking transitions in their pitting toward the 

 AbietineaCj even the most archaic structurally known abietineous 

 type, Prepinus, shows no tendency whatever toward the araucarian 

 form of bordered pit. In the case of Prepinus just referred to, we 

 are moreover forced to the conclusion that we have to do with an 

 extremely ancient coniferous type, since the foliar bundles show an 

 abundant development of true centripetal wood as distinguished 

 from mere transfusion tissue. Further, the leaf traces are 



com 



surrounded by a complicated double sheath of transfusion tissue, 

 which has its exact counterpart in certain Cordaites but not elsewhere. 



affinity 



mno sperms 



is clearly related to the Cretaceous species of Pinus, as is shown in 

 the article cited. An additional argument for the superior antiquity 

 of the Abietineae is afforded by the morphology of the female cone. 

 It is true that Professor Seward, in the memoir cited above, has 



same mor 



of the female cone in the Abietineae and Araucarineae, in view of what 

 he considers to be the slight degree of relationship between them. 

 That the two families must be regarded as somewhat nearly allied 

 we have tried to show^ above. If it be admitted that they are closely 

 connected it follows that a 



common 



strobilus should be possible. If we accept the generally approved 

 explanation of the double cone-scale present in the female cone of 

 the Abietineae, namely, that the upper ovuHferous scale is an axillary 

 structure of shoot value subtending the sterile bract, then we are 

 almost driven to regard the single cone-scale of the Araucarineae with 



