X907] JEFFREY— ARA UCARIOPITYS 



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mainly tracheids, showing the araucarian type of pitting.- Occasion- 

 ally a tracheid may be found in longitudinal sections of our species, 

 broad enough in its terminal region to accomodate a double row of 

 pits, in which case the phenomenon of alternation as well as flattening 

 may be observed, although even the biseriatc pits are sometimes 

 found to be opposite as in the Abietineae. It may be questioned by 

 the reader whether the evidence afforded by the pitting alone is strong 

 enough to decide the Araucarian affinities of the genus we have been 

 describing. We have no inclination to deny the propriety of such a 

 doubt, but we consider it to be removed by the fact that the large 

 number of presumably transitional Araucarians found in the form of 

 well-preserved leafy branches in the Androvette deposits were accom- 

 panied by numerous associated cone-scales, which, where they did not 

 obviously belong to Pinus, WTre also Araucarian and of a transitional 

 type of organization. For a full discussion of this matter the reader 

 is referred to the joint memoir already cited. 



Fig. I J illustrates the short shoot of Araucariopitys as seen in 

 tangential section under low magnification. The brachyblast is 

 present in the upper part of the field. Below it there is a scarcely 

 perceptible disturbance in the arrangement of the tracheids, indicat- 

 ing the position of the foliar trace, to which the short shoot is axillary. 

 It is apparent, from the topography of the tangential section of the 

 wood, that the axillating leaf was better developed in Araucariopitys 

 than is generally the case in Pinus, where the subtending foliar organ 

 is usually obsolete or has degenerated into a mere scale. There 

 are of course in Pinus certain exceptions to this statement in the case 

 of seedlings and the shoots growing out of injured branches. In 

 fig. 14 is represented a more highly magnified view of the section of 

 the same short shoot shown in fig. 13. Fig. 15 represents a radial 

 section through the axis of the short shoot, which at the same time 

 includes a part of the woody cylinder and the pith of the parent axis. 

 In fig. 16 is seen a transverse section through the main axis at the 

 level of exit of one of the brachyblasts. It is easy to determine from 

 the sections just described that the woody cylinder of the short shoot 

 projects little if at all beyond the surface of the wood of the main axis. 

 Figs. 12-17 have all been made from another specimen than that 

 which furnished figs, i, j, 4, 5. Fig. 17 presents a somewhat magni- 



