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There are at least ten methods of preparing antigens, and there is 

 some speculation as to which is the best. I have always held that the 

 simpler method of doing anything is the better and I am striving for 

 simplicity in this matter. The most simple method I think is to grow 

 a sufficient amount of the fungus on suitable culture media, suspend in 

 saline solution, kill, preserve and it is ready for service. Of course all 

 understand that this is the work of a trained bacteriologist. Some of 

 the methods I am using at this time, however, are not quite so simple. 

 Naturally, after so short a time, I have not been able to make an antigen 

 that is my ideal. That is a goal which I will still strive to attain. 



Concerning the matter of injection I wish to say that at present I 

 have found that to make a T incision, pry the bark loose from the 

 vertical portion, paste some tough paper over it with hot paraffin form- 

 ing a little pocket, filling the pocket by using a medicine dropper and 

 sealing with paper and paraffin is my method of choice. How long I 

 shall use this method I haven't the slightest idea. I think a more nearly 

 ideal way would be to insert the Huid under tlie bark with a needle, pro- 

 viding a suitable antigen could be made. I am now experimenting with 

 a little antigen in which tlie active principle is so nearly in solution 

 that I am entertaining the hope of successfully using it with a large 

 needle. If this one is not satisfactory, I shall try another as this 

 method of injecting will have considerable advantage, especially in 

 small plants, although there are many obstacles to overcome before it 

 can gain prestige over the above mentioned method. Several other 

 methods are being used with a variable degree of success and practi- 

 cability. 



What shall we try to immunize.'^ Last year I made the statement 

 that I did not believe it practical to attempt to immunize all the plants 

 in the forest. Besides we would not have much if we did. I there- 

 fore planned to immunize a few varieties to a high degree. This plan 

 I am still holding paramount. I have no doubt tliat after as much work 

 has been done along this line as has been done on the automobile, avia- 

 tion, electricity, etc. many things may be accomplished which we do not 

 deem feasible now. But in order to do it one must have access to a 

 great deal more antigen than I have thus far felt disposed to make. 



Most of us, who had the opportunity as boys, remember favorite 

 chestnut trees which produced exceptionally fine nuts of very large size. 



