Slimmer Meeting:. 89* 



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this time show, when examined closely, little glistening knobs on the 

 top of each elevation. These knobs consist of thousands of spores,, 

 which may be carried off from one fruit to another. 



To the average observer there is something uncanny in the 

 rapidity with which a crop of fine apples is attacked and destroyed in 

 the course of a few days, before one's very eyes, and the consciousness 

 that we appear to be powerless to stop the destruction does not add 

 to one's comfort. 



The very important question in any matter of this kind is. What 

 can de do to stop this disease? Before entering upon this phase of the 

 subject, I wish to invite your attention for a little while to some facts 

 we have been able to discover as to the cause of this disease. It is 

 common practice, well known to all of you, that when we wish to con- 

 quer an enemy, we do our best to discover his weak points : Where 

 he spends his time and what he does, so that we may surprise him 

 when he is not looking. Strange to say, many of us seem to forget 

 that those things which go on about us in the fields and in the or- 

 chards, our insect and fungus-enemies, are in many respects like the- 

 enemy in the trench, always at hand, even when we do not see him. 

 We become aware of the curculio, the borer, the scab, and the bitter 

 rot at certain brief times, and when the enemy is upon us and has 

 beaten us, then we bemoan our fate and speak of hard luck and poor 

 land and what not. Let us, therefore, confront our enemy, the bitter 

 rot, and ask, what is he like, where is he when we do not see him,, 

 how does he spend his time? and perhaps we can catch him unawares. 

 We have found that the diseases of plants are due to two main 

 factors : unfavorable growth condition and attacks of insects or fungi. 

 The bitter rot disease belongs to the second class. It is caused by 

 a fungus, which grows in the ripened fruit and by so doing brings 

 about its decay. All fungi propagate by means of spores of one kind 

 or another, small microscopic cells, which are carried about by the 

 wind, by insects, birds, water and other agencies. If we were to 

 examine one of those glistening drops on the top of one of the black 



knobs mentioned above, as occurring in the center 

 of a rotted area, we would find that it consisted of 

 a great mass of spores, such as you see before you 

 (Figure i). They are eliptical bodies, which 

 when brought into a drop of water, germinate or 

 sprout very readily. At first one or two threads 

 come out from each spore. (Figure ^), which 

 rapidly lengthen the branch. If sufficient food, for instance, sugar is 

 given them these threads grow out in all directions with equal rapidity, 

 and soon form a circle, which increases in diameter very quickly. If 



