43S 



(b) Anatomy. 



Microscopically the timber of this and other Podocarpus species cannot lay 

 anv great claim to affinity with that of either Agathis or Araucarin, being more 

 closelv related in structure, perhaps, to that of Callitris. 



The walls of the tracheids and medullary rays are more slender than in almost 

 any other Australian genus of the Order, whilst the lumina are tlie narrowest 

 of all ; altogether the sections convey the idea of sleriderness, compared with those 

 of cognate genera. No traces of marginal tracheids in the rays were found. The 

 bordered pits are on the radial and occasionally tangential walls, and are both 

 single and distant in the lumina. 



In the xylem there are no linear stretches of the manganese compound, as in 

 Callitris, and although a transverse section shows it fairly distributed, yet the 

 other two sections prove that there are only small particles present. In the ray 

 cells it is e.xceptional to find it. In fact, there is less of this substance in the 

 wood material than obtains in the other genera. i^See article on the manganese 

 compound. ~ 



The tangential section is of some value in diagnostic work, for one does 

 not find the regular fusiform character of the Callitris raj's or the linear features 

 of the Araucaria, but here and there the spindle-shaped rays are composed of 

 varying numbers of cells in height, intermixed with numerous ravs one or two 

 or three cells high, giving the walls a chain-like appearance. This feature does 

 not realise in any other Conifer examined. 



The simple cells are not very pronounced in the rays, and mostly only 

 one occupies the space between the lumina ; the perforation is sometimes circular 

 and sometimes an oblique slit, as in Figures 293-6. 



{d) Forestry. 

 (\'ide remarks under Timber.) 



V. BARK. 



Anatomy. 



This is a characteristic bark, although showing some affinities to that of 

 the Callitris species, the main point of differentiation being the almost entire 

 absence of periderm bands, and the more fully developed sieve tubes, for they 

 occupy a much larger space between the sclerenchymatous fibres and the 

 parenchymatous vessels, and are well shown in Figure 297. 



The cambium is a very narrow band, and is succeeded in regular concen- 

 tric uniseriate rings of sclerenchymatous fibres, sieve tubes, and parenchymatous 

 tissue. Figures 297-8. 



