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dead material and from there attacked and brought down that tree and 

 sometimes the whole orchard. 



It is not a very cheerful idea to think that a small street urchin throw- 

 ing a stone at one of your cherry trees may cause the loss of the whole 

 orchard, if only the special organisms are present to establish themselves 

 in the injured spot. This is no exaggeration, several similar cases are on 

 record, and the only way to protect our orchards is to remove all causes 

 of infection and to keep all trees as healthy as possible. In 1904 an 

 epidemic was raging in the cherry orchards in Germany, and the trouble 

 was traced back to one orchard where a large tree had been struck by 

 lightning during a severe thunderstorm. The owner of that orchard left 

 that tree as it was and one of these dangerous ascomycetes took possession 

 of that severely wounded tree and spread from there over a large area. 

 The loss involved in this epidemic was considerable, all caused by the 

 ignorance of one man. It was here a case of ignorance, for the owner of 

 the orchard did not know that this damaged tree was dangerous to the 

 other trees in the neighbourhood, and at present very few people would 

 view the matter from such a standpoint. In this respect we have to 

 struggle through the same difficulties as in the time that people did not 

 see the necessity of sanitary and hygienic conditions for themselves. This 

 problem is solved; everybody knows the danger of the surrounding bac- 

 teria and the necessity of taking measures. The time will come when 

 we will do the same for our orchards. 



To finish this address I will give the results of our personal investiga- 

 tions of several cases in which cherry trees suddenly died under appear- 

 ance of gummosis. We have always been able to isolate an organism and 

 to locate the spot from which the infection started, and we were always 

 particularly anxious to find out in what way such a tree had become 

 injured, and the results of some of our findings were most surprising. In 

 five cases blackbirds had been picking unripe cherries; in two instances 

 leaves had been torn off by visitors, in five cases there had been frost when 

 the trees were in bloom, and last, but not least, two cats had been fighting 

 in a cherry tree. 



These were only a few instances in which we could detect the cause 

 with certainty. 



Add to this the injuries caused by insects and you will come to the 

 conclusion that at present there should not be one cherry tree on this 

 earth. It is with this as with our human troubles, theoretically, we should 

 all be destroyed by bacteria before we have seen daylight, but there are 

 such things as luck and chance in this world and we must thank them for 

 the fact that our orchards are in such good condition in spite of the fact 

 that we do nothing to save them. 



