ii4 



In viewing the sections depicted it will be seen that the three leaves form 

 parts of one whole, and together with the central cylinder formed bv the branchlet 

 bundles, no doubt act in unison in the performance of these physiological functions 

 necessary in the life history of the tree or branchlet. 



In Figures 60 and 61 several similar features are shown. Figure 60 was 

 cut through the middle of the oil cavities, which latter occupy a goodly proportion 



of the leaf area; whilst Figure 



61 was cut a little lower down 



the branchlet. The cluster of 



parench^-matous cells between 



the central axis and the decur- 



rent channel are almost devoid 



of contents as obtains in some 



other species, as for instance, 



C. robiista, or C. rhomboidea 



especially. The palisade cells are 



seen closely packed and narrow, 



and the assimilatory surface with 



its la37ers of epidermal and hj'po- 



dermal cells is also well defined. 



The epidermal cells are much 



larger than the hypodermal in 



this instance. A bundle occurs in each leaf on the inner side of the oil cavity, and 



what is of particular interest in these sections is that they show clearl}- an extension 



of the xylem of these bundles into a mass or collection of short tracheids, a feature 



recorded in "Taxus," by Frank, and called by Mohl, transfusion tissue — a term 



used throughout this work to describe this structure. If examined under a 3-in. 



or 4-in. lens the details are especially distinct, and will be found to accord with 



those given under other species. 



Figure 60. — Trans\erse section through central axis (branchlet) and 

 three decurrent leaves in the locality of the oil cavities. 

 C. prof>:tt<jtia, x 70. 



(c) Chemistry of the Leaf Oil. 



No. 1. — This material was received from South Australia, i8th May, 1905, 

 and was sent to us by Mr. Gill, the Conservator of Forests for that State. The 

 whole of the fruits were removed before distillation, so that the oil is that of the 

 leaves and terminal branchlets only. The distillations were continued for six 

 hours; and 278 lb. of material gave 18 oz. of oil, equal to 0-41 percent. The crude 

 oil was but little coloured, and had an odour similar to the Callitris oils belonging 

 to the C. glauca group. It became somewhat insoluble in alcohol on keeping, and 

 did not form a clear solution with ten volumes of 90 per cent, alcohol. During 

 the time which has elapsed since it was distilled, no resin has deposited upon the 

 sides of the bottle as was the case with all our samples of C. glauca, and in that 



