CONIFERALES 



59 



garded as giving evidence of such a derivation. In other par- 

 ticulars, also, Cephalotaxus seems to be the most cycadlike of 

 the Conifers. 



Eesin ducts seem to be present in all Conifers except Taxus, 

 always occurring in the leaves and in the cortex of the stem. In 



6 h 



Fig. 43. — A cube from the secondary wood of Fimis Zaricio, reconstructed from three 

 camera drawings : in cross section at the left a few rows of small thick-walled cells 

 of the autumn wood are shown, and at the right the larger thinner-walled cells of 

 the spring wood ; tr, transverse section ; Ir, longitudinal radial section ; It, longi- 

 tudinal tangential section ; m, medullary ray ; 6, bordered pit ; rf, simple pit ; x 400. 



different genera they occur also in all other regions ; for exam- 

 ple, in the primary and secondary xylem, and certain pith rays 

 of Pinus ; in the primary and secondary phloem of both stem and 

 root in Araucaria, etc. They are absent from the root in many 

 genera, and when present never occur in the cortex. These 



