SOriKTY OF NORTHERN ILI-INOIS. 225 



tioii: wliat I have written in the last para^i'apli is the result. Not 

 on every ritl^e or knoll will trees sutler more by drouth than upon 

 adjoininjj: Hat lanil: l)ut this is <;,.iierally the case in Fllinois. If so. 

 has not our teaching as to orchard sites l)een erroiRH)Us? No one 

 would, in his senses, advocate puttin*^ apple trees into undrained 

 .sloughs; but it does appear that land needing and having good tile 

 drains is better ada])ted for an a])ple orchard in our State than the 

 dry hills and slo}tes. 



If the foregoing is true, ever}' means within the cultivator's art 

 should be used to gain a good summer's grow^th witliout a July or 

 August pinch — such as frequent pulverizing of the surface soil, 

 mulching, the use of clover as a cover to the earth, etc. Trees that are 

 permitted to overbear are more lial)le to injury for similar reasons to 

 tho.se stated above. Prevention can in part be secured ]>y heaping the 

 earth late in autumn against the trunk, and ))rolial)ly any shelter 

 from the winter's sun will do some good. The more changes from 

 Wt\rm to cold and the reverse the greater the amount of water in the 

 tissues. A ma[)le tree yields more sap from a tap on the south side 

 than a similar one on the north; but the })er cent, of sugar is 

 greater in that from the north; two equally significant facts for our 

 purpose. The tree is more liable to burst on the south side, because 

 there is in the tissues of that side really more litpiid water. When 

 shelter from the sun is offered, bursting may occur on any side, but 

 is less likely to take place. 



DISCUS8I0X. 



Dr. Humi»hrey -- 1 think Professor liurrill makes too strong a 

 statement in the first part of his pa})er. I think there is a weaken- 

 ing of the tree before the bacteria attack it: think his statement too 

 broad on this point. I think the plant is damaged or diseased before 

 the bacteria commence to woi-k on it — the ailment of the plant 

 making its condition favorable to the attack and growth of the bac- 

 teria. 



President Slade — I feel that I)i-. ITumphreys ))a})er was a very 

 good and interesting one, and he has come a long way to be with us. 

 1 am very glad that we have him with us. He is. as yon have doubt- 

 less observed, a great worker, and 1 want to thank him lor his good 

 and valuable ])aper. 



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