160 OYSTER-SHELL BAKE LOUSE. 



It was further remarked that experience had shown that very strong 

 applications, such as undiluted soft soap, failed to destroy the vitality 

 of the eggs under their protecting shield ; but that simply greasing 

 them over was fatal to them, probably by closing the pores and thus 

 excluding the air. The question then naturally arose whether greasy 

 applications would be injurious to the tree, and it appeared that the 

 published testimony upon this subject is quite conflicting. 



At the time of writing that article the season had gone by for experi- 

 menting in this matter ; but in the spring which has since intervened 

 (1871), I performed the following experiments for the purpose of fur- 

 ther testing this point. 



On the 30th of March, the buds not having yet expanded, I selected 

 six thrifty five-year-old apple trees, of three diflerei)t varieties, and 

 applied to two of them simple lard, greasing over every part of the 

 trees, trunk, branches and twigs. To two others keroieae oil was ap- 

 plied in the same manner. To the other two linseed oil was applied ; 

 but in this case, to vary the experiment, the terminal twigs were omit- 

 ted. None of these trees were eventually damaged by the applications. 

 Upon those to which the lard and the linseed oil were applied, no efiect 

 was perceived. They leafed out as early and looked as well as other 

 trees standing beside them. The kerosene, as might have been antici- 

 pated, acted more severely. It killed or seriously damaged all the first 

 buds, and the trees were several weeks later in leafing out than the 

 others, but at an examination of them on the fifth of July, no difier- 

 ence could be seen in the quantity or healthiness of the foliage, from 

 that on the other trees. One efiect of the kerosene is deserving of 

 notice. The check thus given to one of these trees had an effect simi- 

 ]?.r to girdling or root-pruning, namely : that of throwing it into pre- 

 mature bearing — this tree producing an apple though still standing in 

 the nursery row. 



In further illustration of the effect of greasy application to apple- 

 trees, I will add that Mr. James Grotty, an intelligent Irishman, in 

 whose nursery the above experiments were performed, stated to me 

 that when he lived in Ireland it was a common practice to annoint with 

 linseed oil apple-trees large enough to bear, but which were growing too 

 much to wood. The whole tree was annointed except the smallest 

 twigs and fruit-spurs. The effect was to check the growth of the tree 

 and put it into a bearing condition. The operation was not supposed to 

 permanently injure the trees. 



