200 R. T. BAKER AND H. G. SMITH. 



of parenchyma ; the former are the lighter coloured vessels, 

 and the latter the darker ones which become paler as 

 tliey approach the phloem. In a longitudinal section, spiral 

 and annular vessels occur in this portion of the vascular 

 bundle, the xylem being developed centripetally. The 

 phloem borders the xylem in some thickness with many 

 radiating or medullary rays, and concentric bands of vessels. 

 The ventral (protoxylem) and dorsal (phloem) sides of the 

 fan or wedge shaped portion of the stele are subtended by 

 the pericycle, a homogeneous mass composed of thickened 

 cells which may be regarded as transfusion tissue, and in 

 view of the usual shape of tracheids of the xylem we can 

 hardly hesitate perhaps to class them as such, which bodies 

 appear to be the sine qua non of this substance. The 

 structure of the cells favours then the statement by Scheit, 1 

 that its origin lies in the xylem and is homologous with 

 that substance, although the phloem in its outer edges 

 touches in this instance the endodermic circle and so bars 

 access to the xylem to those cells in juxtaposition to the 

 phloem. 



Pig. 14 is a section cut longitudinally through the phloem 

 and xylem and shows the vessels of this transfusion tissue 

 in their long axis, their resemblance to the tracheids of the 

 xylem contiguous with the cambium, is in accord with 

 Scheit's theory as to their origin. 



Chemistry.— The yield of oil obtained from this species 

 by distillation on commercial lines, was 1*246°/°, 943 lbs. of 

 leaves and terminal branchlets giving 188 ounces of oil. 

 The material was collected in the month of March, at 

 Wyalong, New South Wales. The crude oil was but slightly 

 coloured, being yellowish in tint. It had a strong cajuput 

 odour, with but a slight indication of the presence of 

 volatile aldehydes; in this respect it was different from the 



1 Indische Zeitschr. f. Naturwiss., Band xiv., 1883. 



