4 Proceedings. 



out a long transparent thread or tube, which had found its 

 way out at the stomata of the leaf. One reason of its 

 previous non-discovery was manifest, viz., its close resem- 

 blance to the cells of the leaf, from which it could hardly be 

 distinguished. Further observations, extending over a period 

 of many months, confirmed Mr. Worthington Smith's dis- 

 coveries, and it soon became an accepted fact that an 

 important discovery had been made, and a great and 

 important step had been taken in the direction of finding 

 out the nature of this most destructive disease. 



Since 1876 not much of importance has been done 

 towards the further investigation of the Peronospora infestans. 

 Multitudes of suggestions have been made as to the best way 

 of getting rid of its inflictions, but hardly anything reaUy 

 feasible has ever yet been offered. Almost the only plan I 

 can think of as at all likely to succeed in avoiding the 

 presence of the enemy is to cultivate the earliest and perhaps 

 the very latest varieties ; by this means the crops would not 

 be so much, if at all, exposed to danger during the critical 

 period of late summer and early autumn, when the spores 

 begin to germinate. 



Dr. Bossey made some remarks on the subject of the 

 paper, and called attention to the modes adopted for the 

 prevention of the disease. He recommended the growth of 

 Potatoes with thick smooth cuticle and short haulm as best 

 calculated to resist the attacks. He also suggested that the 

 resting- spores might be destroyed by chemical agents mixed 

 with the soil. 



Mr. Gill remarked that it is easy to destroy the specimens 

 in a laboratory, but that the destructive agent, in order to be 

 really of practical value, must be cheap, and easily applied. 



Mr. Cheal mentioned that glasses covered with glycerine 

 had been found to catch the spores when placed in other 

 fields in the neighbourhood of that affected by the disease, 

 thus showing how widely and abundantly the spores become 

 disseminated. He stated that the Potato is a native of the 

 uplands of Mexico, and grows in a moderately cool climate. 



Dr. Bossey read a paper on ' The Hairs of Plants as 



