350 



There are articles on the susceptibility of Eucalypts to drought in The Australian 

 Forestry Journal for May and July, 1923, in which the subject of the concentration of 

 salts in ground-water is dealt with. Although it is so very important, it is one which 

 has not been dealt with, at all events, quantitatively, except to a very limited extent, 

 but, simultaneously with the better management of Australian forests, it will be admitted 

 into the category of pressing matters. 



If the Forestry Departments of the various Australian States have records as 

 to the effect of drought on the various species, it would be desirable to publish them. 



NOTE ON SPECIES OF APPARENTLY ANOMALOUS RANGE. 



This is one of the many phases of the subject that I have only time to barely 

 touch upon. 



Take, for example, E. Bakeri, E. hybrida, E. squamosa. These are three eastern 

 Bisectse (a group vastly predominant in Western Australia). They are fundamentally 

 allied. 



E. Bakeri may be Eremean. E. hybrida grows in saline surroundings, and hence 

 is retarded in development. The same conditions may perhaps affect E. squamosa. 

 The student of distribution in Eucalyptus will study that aspect presented in Dr. Delf 's 

 paper. 



E. Marion Delf. — " The Meaning of Xerophily " (Journal of Ecology, III, 110, 

 1915). 



The author points out the confusion which has arisen in regard to the meaning 

 of xerophily, and in the " Summary and Conclusions " says : " From examination of 

 all the evidence, it is clear that xerophily cannot be adequately defined in terms of 

 habitat, of anatomy, or of physiology alone . . . Edaphic drought may be met 

 with in at least three different ways — (1) by the development of a deep root-system, 

 penetrating to a constant water-supply in the subsoil; (2) by the production of a 

 generalised root-system with tissues which can develop very high osmotic pressures, 

 so that absorption is possible, even in air-dry soil ; (3) by a superficial root-system 

 with capacity to form adventitious collecting rootlets rapidly after rainfall (characteristic 

 especially of Cactaceae) ... On the whole, the result of ecological work of all kinds 

 tends to show that the plant and its environment vary together, and that neither is 

 wholly without effect upon the other . . ." 



There are other contrivances to resist drought, e.g., the physiological properties 

 of bog-water, which contains humus acids and is often cold in addition. Then water 

 may contain a certain percentage of salt, and so we may have a physiological drough , 

 with water everywhere. We have to ascertain in what way and to what extent this 

 may influence the welfare and, therefore, the distribution of Eucalypts. 



