AUSTRALIAN MELALEUCAS AND THEIR ESSENTIAL OILS. 199 



cells surrounding the pericycle of the stele as the number 

 of glands increase in these sections. 



In Fig. 8, these endodermic cells, whilst forming a feature 

 of the picture, yet are comparatively few in number com- 

 pared to those of figure 3. This varying number and 

 irregular distribution of oil glands as shown in the various 

 sections proves that these organs are true spherical bodies 

 and not canals or ducts. 



Fig. 9 is an enlargement showing the gland in the 

 lower right hand corner of the previous figure. It gives 

 the detail clearly and more particularly of (1) the conical 

 cells of the epidermis : (2) a broken wall cell of the wall of 

 lysigenous oil gland ; whilst one of the smaller vascular 

 bundles appears to be quite compressed between the two 

 oil glands. The shape of the lower epidermal cells is quite 

 unique, and none of similar character appear to have been 

 previously recorded. 



Fig. 11, magnified 160. This photograph is reproduced 

 to show the intermixing of the spongy parenchymatous 

 cells with those of the endodermis. A collateral fibro- 

 vascular bundle is well brought out on the right. 



Fig. 12, is a 160 magnification of a central portion of a 

 section in which were found two cavities or lysigenous 

 intercellular spaces near the centre or amongst the pro- 

 toxylem. The presence of a few spongy parenchymatous 

 cells can be traced between the endodermic cells and the 

 palisade parenchyma. 



Fig. 13 is a 210 magnification of the central fibro-vascular 

 bundle of Fig. 7, showing the well marked endodermic cells 

 which form a continuous border, whilst a few are to be 

 seen scattered amongst the internal structure and several 

 amongst the protoxylem cells. From these latter, radiate 

 in rows the tracheids of the xylem alternating with those 



