1911-12.] BOTANICAL SOCIETY OF EDINBURGH 17 



Everyone interested in the cultivation of plants should 

 endeavour to make himself familiar with the appearance 

 and effect, and possibly the botanical names, of the 

 commoner disease-causing fungi, also the general pre- 

 ventive measures to be adopted to prevent their spread. 

 It is of the highest importance that a plant disease of any 

 kind should be recognised in its earliest stages, as it is then 

 that its spread may be prevented either by a timely spray- 

 ing or by the more drastic method of removing the diseased 

 individuals and burning them to make sure the disease- 

 causing fungus is destro} T ed. It usually happens that 

 before the advice of the plant pathologist is sought, the 

 disease has made itself strikingly apparent by the amount 

 of damage done. It is then often too late to effect a cure. 



On broader lines these remarks which apply to the 

 individual appty equally to the State. We have seen 

 how the Governments of other countries have established 

 Departments to watch over the health of cultivated plants, 

 and they are ready at a moment's notice, so to speak, to 

 aid these Departments by special legislation should occasion 

 arise in the shape of a threatened epidemic. 



True, our own Government has passed special Acts with 

 the view of preventing epidemics, but, unfortunately, these 

 special laws have been so tardy and so long delayed that 

 their effect on the disease may be the same as the proverbial 

 delay in locking the stable door, and in any case there is 

 not sufficient supervision to ensure that these special laws 

 are carried out so as to be of real value. 



From the earliest times we have records that cultivated 

 plants were subject to blights, pestilence, and disease, which 

 the earlier cultivators of the soil attributed to various 

 causes (moon, stars, etc.), but we also find the weather, 

 climate, and soil held responsible for various brands, rusts : 

 and cankers. The existence of parasites or the phenomenon 

 of parasitism among plants was undreamt of. Still, we 

 have here a foreshadowing of the study of the effect of 

 the physical environment on the health of plants. We 

 know now that certain kinds of weather and climatic 

 conditions predispose plants to certain kinds of disease, 

 whose life-histories we know, and we also know that their 

 relationship to their host plants is regulated by external 



TRANS. BOT. SOC. EDIN. VOL. XXVI. 2 



