360 



cause of all tlio mischief; thus, one writing at that time, says: 

 " those of my trees that are affected are growing in my liighly 

 manured vegetable garden, and all those in my grass land, 

 "which is seldom manured, are entirely free from the disease, 

 and my opinion is, that a corrupt state of the juices arising 

 from excessive manuring is the cause of the evil." Anoth- 

 er writes: " We doubt whether the ' Scolytus' can be the 

 perpetrator of all the mischief ; a gardener of my acquain- 

 tance had honeysuckles growing around some of his Pear 

 trees ; these were then free from blight. After clearing 

 away these vines, he manured and dug over the land ; he thus 

 dug the grave for his fine trees. Let us suffer our trees, as 

 they are coming- into a bearing state to vegetate natvrcMi/ ; 

 they will be a little more tardy in growing up, but they will 

 be hardy, healthy, and bear well. That ground may be too 

 rich for Pear trees, there can be no doubt, producing the 

 disease of repletion." SHU another: "My trees in highly 

 manured land, or in low and rich soils, have been most seri- 

 ously affected ; while those on my high and uncultivated 

 soil, have escaped infection. So far my experience accords 

 with Puhamel's theory." 



Other instances were brought forward by Mr. Ives. He 

 spoke of recent article from Illinois, where it was computed 

 that the loss of fruit for a few years past in that State, would 

 amount to three millions of dollars, and that this destruction 

 was said to be owing to " the retentive, clayey subsoil, and 

 that farmers are now plowing furrows and throwing up the 

 land into ridges, commencing at the same ridges, and ending 

 at the same furrow, to remedy this evil." He did not ap- 

 prehend that this could be simply owing to the clayey sub- 

 soil, provided it does not retain water, for here we find that 

 the Pear tree flourishes better on land with a subsoil or pan 

 of clay, which prevents the roots running too deep. The 

 difficulty, he thought, was in the adhesiveness or peculiar 

 quality of their clay which prevents the percolation of water 

 through it. 



He closed by a reference to the blight of the Pear, so com- 

 mon at the West, believing that there are in general two 

 forms of Blight, one caused by a severe scald, produced by 

 taking off or denuding young trees of their lateral or side 

 branches, thereby exposing their naked trunks to the sun, 



