1015] 



AASE—M EGASPOROPHYLLS OF CONIFERS 



301 



Araucarla, is absent, but the general appearance of a slight eleva- 

 tion behind the ovule suggests the possibility of a fused body. 

 The vascular supply begins as a single stout trace a little to one 

 side at the base of the short wide cylinder gap. The trace increases 

 in size, and in the outer one-third of the cortex a branching begins 

 which in the lamina of the scale results in about thirteen bundles. 

 About half-way between the insertion of the sporophyll and the 

 insertion of the ovule a small strand splits off from one of the median 

 bundles, swings around 1S0 , and becomes an inverted bundle 



Figs. 155-161. — Araucaria Rulci, young sporophyll: figs. 155-160, course of 

 bundles from strobilus axis to free portion of bract, upper bundles differentiated in 

 cortex and base of sporophyll (B, bract; 5, scale; 0, ovule); fig. 161, longitudinal 

 section of sporophyll; X8.5. 



opposite its sister bundle. The inverted strand may fork, and also 

 inverted strands may spring from several of the median lower bundles 

 and these strands may divide so that the number of upper bundles 

 varies from one to several. In any case, each of the upper 

 bundles, after giving off a phloem-like strand to each ovule, ends in 

 large irregular tracheids. 



PODOCARPINEAE 



In most of the Podocarpineae a definite strobilus is absent, the 

 fructification consisting in most cases of one or two fertile sporo- 

 phylls. In many forms there is a tendency for some part of the 

 fructification to mature fleshy. 



