6o THE CONNECTICUT POMOLOGICAL SOCIETY. 



sites. Investigations along these lines have been wholly nega- 

 tive, although they have been pursued, especially in years past^ 

 with great persistence and thoroughness. It seems almost 

 certain that had it been an ordinary germ or bacillus the 

 methods employed would have revealed the same. It is hard 

 for me to believe that the disease is not a parasitic disease,, 

 however, and that some day the parasitic organism will be 

 found. The failure to find the cause of the disease or any 

 definite parasite associated with it puts this discussion of peach 

 yellows, which I am called upon to give you, on a dififerent 

 plane from that of the ordinary fungous or bacterial disease 

 of plants. The expert pathologist, on account of this con- 

 dition of affairs, has no particular advantage in obtaining 

 knowledge about this disease over the horticulturist or or- 

 chardist. His special methods of microscopical and bacterio- 

 logical research have failed. He, therefore, lacks the advan- 

 tage and light on the subject which these methods ordinarily 

 give him. 



It is true that, by comparison with definitely known germ 

 diseases, such as pear blight, and with his general knowledge 

 of plant physiology and pathology, he may possibly steer 

 clear of false theories and conclusions. Such an advantage, 

 however, is mainly negative and gives little help of the posi- 

 tive sort. 



I hope I have made it clear, therefore, that in a discus- 

 sion of peach yellows the writer has no peculiar advantage 

 over his hearers. 



What is Knoitm about YcUozvs. With this under- 

 standing, therefore, and with this clear admission of the lack 

 of knowledge, let us proceed to gather all the known facts 

 about this disease, especially those which will throw light on 

 combating the malady in Connecticut. Let us bring up ques- 

 tions concerning this destructive malady of the peach, and 

 from all the known facts, experiments and orchard experi- 

 ence available, answer them as far as we can. By all means, 

 let us bring out the definitely known facts and separate them 

 from the theories more or less probable. 



