56 TRANSACTIONS OF THE ILLINOIS 



gamous and cryptogamous classes of plants. There are no vacuums 

 or lines in nature. I don't know whether fungi attack living or 

 dead matter. It can't be held until we are able to examine the 

 ultimate particles of matter. Dr. Hull says the innoculation of 

 healthy trees produces disease ; but the use of the knife in the very 

 act of innoculation produced abundance of diseased matter. I think 

 dilute carbolic acid would be a good thing for killing fungi, and 

 meant to have suggested it in my paper. 



Tice — I have used carbolic acid on grapes with good success, put- 

 ting in 1 pint to 80 or 100 of water. 



Warder — I have been exceedingly interested in the two papers of 

 Dr. Hull and Prof. Turner. They are the result of great study on 

 their part, and will in turn cause us who hear them to study. I am 

 opposed, however, to one or two of the positions. Pear blight is a 

 fungoid growth first appearing on the outer bark. Fungi increase in 

 two ways, by spores and by the mycelium. By spores is the more 

 common way, though the other is to be considered. The mycelium 

 propagates itself by extension in contiguous tissue. Blight, com- 

 mencing in the bark, is sometimes simply strangulation, and is not 

 necessary poisonous. It gradually girdles the tree and chokes it to 

 death. The tree seems healthy up to the very moment of strangu- 

 lation. 



Prof. Turner speaks of the patches of bark where blight begins 

 being oval in shape. They are rather oblong and irregular. 



Shepherd — It is a healthy conclusion that we are all coming to 

 that we know nothing about this. I have observed blight very long 

 and failed as well. In my section we have several varieties of Oak, 

 Linden, Wild Cherry, Ash, Sugar Maple, Aspen and Poplar, all af- 

 fected with what appears to be blight. I would like to distinguish 

 between all these deaths that we call blights. There is a greater 

 fatality in our forests than in our orchards, although I have taken 

 out 100 pear trees in a season. 



The first symptoms of the breaking out of blight, is a scent of 

 decomposing vegetable matter. I have seen trees blight in sections, 

 a part of the trunk being dead, with live wood above and below it. 



