36 



JOURNAL OF THE ROYAL HORTICULTURAL SOCIETY. 



Some think it is due to lack of food in the soil, but not always. I can 

 produce silver leaf. 



Mr. Bunyard : By inoculation ? 



Mr. Massee : No, but by planting fruit trees close to the drain from 

 a stable. 



Mr. Bunyard : That does not look like lack of nutriment. 

 Mr. Massee : No. 



Mr. Bunyard : It would rather seem to be the effect of overfeeding. 



Mr. Massee : White root-rot is often an exceedingly common and 

 unsuspected source of danger. When a premature yellowing of the foliage 

 is observed, expose the root and see whether you can detect the presence 

 of a white mildew on the root or in the soil. If the white fungus is 

 found under the bark of the root and at the collar, attempting a cure is 

 hopeless. If the attack is only slight and superficial, procure a supply of 

 boiling water and throw it on the roots and surrounding soil. No harm 

 is done to the tree, as the temperature of the water is lowered before it 

 injures the roots, but it will kill the fungus. Mix the soil on replacing 

 with a sprinkling of quicklime and powdered sulphur. 



Mr. Cecil Warburton, M.A. (Zoologist to the Eoyal Agricultural 

 Society) : If there is to be any discussion on the many interesting points 

 already raised, I must cut my remarks very short indeed. Mr. Theobald 

 said he was thankful I was to deal with the Black Currant Gall mite, 

 thereby no doubt implying that there was little satisfactory to say about 

 it. I think, however, the time has come when a summing up of our 

 knowledge with regard to it may be useful. The mites live for the most 

 part inside the buds. They are extremely small, about one-hundredth of 

 an inch long and very much narrower, so that it is not very astonishing 

 that we have made such slow progress in finding out how they live ; but 

 our knowledge of their life-history is at length fairly complete. Eggs 

 are laid during every month of the year, and the mites go on increasing 

 until one of two things happens. Either they have not done a great deal 

 of harm, in which case the infested bud is not prevented from developing, 

 or they have eventually killed the bud, in which case it dries up and the 

 mites leave because they have no longer a suitable place to live in. They 

 leave the developing buds and, having nowhere to go, perish. Later they 

 leave the buds which are dried up and they go into the new buds. I 

 believe that those which survive are entirely in the new buds. Our 

 experience as to the effect of treatment is extremely irregular. You may 

 use the most drastic measures sometimes and yet you have the mite 

 recur. On the other hand, you may use mild measures and almost appear 

 to succeed. One gap in our knowledge is as to what becomes of those 

 mites which do not gain access to the new buds. Do they go down into 

 the ground or do they lurk in the lower portions of the bushes '? And 

 here is our difficulty. I have not been able to find, and no one else has 

 been able to find, these mites living in the soil. I have not been, and 

 no one else has been, able to find these mites living low down on the 

 stems of the bushes. Yet it is perfectly certain that one or the other of 

 these things takes place. Otherwise you cannot account for the fact 

 that you sometimes cut bushes down to the ground and the mite will 

 reappear. Two considerations lead me to believe that it is always in the 



