136 PRESIDENT S ADDRESS — SECTION D. 



principles established by the plant physiologist. The only hope of 

 diminishing the losses of millions a year which are caused by 

 various plant d it eases such as rusts, smuts, blights, mildews etc., 

 lies in encouraging the> investigaticais of the plant pathologist, and 

 in training those who can put his results to practical applica- 

 tion. The identification of M'eeds and a knowledge of their pro- 

 perties is rendered possible by the facts accumulated and by the 

 labour expended by the* syj^^tematic botanist. Without such know- 

 ledge the introduction of new plants is a very hazardous proceed- 

 ing. If a botanist had been consulted before prickly pear was 

 introduced into Australia an egregious piece of folly would have 

 been avoided. When a plant was required to check sand drifts 

 in coastal districts a botanist was consulted. The result was the 

 introduction of Marram grass, which has amply justified itself 

 and its sponsor, the late Baron Von Mueller. The classification of 

 economic plants, a knowledge of their structure, properties and 

 classification, we owe entirely to botanical workers, and it is in- 

 teresting to note that in some cases, notably with fibre plants, 

 structural investigations which at first appeared to be of purely 

 academic interest have proved to be of great practical import- 

 ance. The same applies to certain investigations upon the struc- 

 ture of timber. 



The scientific plant and animal breeder bases his work upon 

 principles established by the botanist and zoologist, and no experi- 

 ments on cross breeding in plants were possible until botanists 

 had established what was the function of the pollen, a discovery 

 which only dates back two centuries or so. 



The relations of botany to forestry are so close and so manifold 

 that it is almost permissible to regard forestry as a practical ap- 

 plication of botanical science in regard to timber trees. At least 

 without the knowledge which the botanist has collected and handed 

 to him, the forester would find it difficult to meet even some of 

 the simpler of the difficult problems which continually confront 

 him. The relations of botany to medicine can not be wholly 

 neglected, although the days when the medical man was also of 

 necessity a herbalist and collected his own remedies has long since 

 gone by. Nevertheless very many of the drugs used in medicine 

 are derived from plants, and much of our knowledge of their 

 distributioai, use and properties dates back to the early herbalistic 

 days. In addition some of the practical applications of physio- 

 logy to medicine are based ixpon the discoveries of botanists. 

 Osmotic pressure was first accurately measured by a botanist, and 

 only a man sure of his science and its methods would have ven- 

 tured to publish measurements which at the time must have 

 seemed ridiculous, namely, the existence in plant cells whose walls 

 are thinner than the finest tissue paper, of pressures of as much 

 as 50-150 pounds per square inch. 



