214 M. B. WELCH. 



e.g., a protein body, would tend to inhibit coalescence of 

 these minute droplets, and this apparently is what occurs. 

 An artificial emulsion of Eucalyptus oil was prepared and 

 stabilised by the addition of a protective body, the magni- 

 tude of the particles of the disperse phase being approxi- 

 mately of the same order as those in the oil gland. The 

 addition of dilute alcohol caused a breaking up of the 

 emulsion, in some respects a parallel case to that mentioned 

 above. 



The following is a summary of the results obtained by 

 treating, with different strengths of alcohol, sections of 

 the leaves of several of the species: — 



E. AUSTRALIANA. 



In the majority of cases the cavity was not completely 

 filled, but showed contraction from the sides, or even large 

 bubbles. The addition of 35% alcohol caused the latter to 

 burst and consequent contraction ensued. 50% alcohol 

 sometimes caused the contracted mass to again rupture* 

 when it lined the wall of the gland. Total disappearance 

 occurred in 50 - 70% alcohol. 



E. GLOBULUS. 



Contents minutely granular, little change occurring up 

 to 80% when small droplets formed. In 90% contraction 

 occurred and the mass became darker in colour, finally 

 going into complete solution in 95%. 



E. OLEOSA. 



Contents with dark coloured granules and small droplets* 

 the latter running together with 35%. Contraction occurred 

 in 50% and the granules increased in number on standing, 

 but cleared again with additional 50%. In 70% the struc- 

 ture became more densely granular, forming droplets in 85% 

 with slow contraction, and finally disappearing in 95%. 



