OF THE CANKER, AND GUM. 317 



hard frost setting in after it kills the young shoots : 

 these, if left on the tree, will bring on the 

 canker, and increase it rapidly. Birds and insects 

 devouring the buds will have the same effect. 



Careless people frequently leave the dead shoots 

 on the tree throughout the Summer, which will 

 infallibly bring on the canker. Some even leave 

 them for years, until the tree is totally killed. 

 They should be cut off in the end of April, or 

 beginning of May ; as by that time you will be 

 able to see how far the disease has advanced, I 

 would advise to cut two or three buds, or even 

 more, below the apparently diseased part, as the 

 canker frequently reaches a great way farther in 

 the heart of the shoot than it appears to do on the 

 outside : you must cut down till the brown colour 

 in the shoot disappears, and nothing remains but 

 sound white wood. 



The truth of the foregoing observations will 

 appear evident to any person who takes notice of 

 the Apple-trees with their mutilated stag-looking 

 heads, as he rides or walks along the road. 



It is a general opinion, that the canker in all 

 trees proceeds from the nature of the ground in 

 w^hich they are planted ; such as a sour clay, a 

 shingly or gravelly soil, &c. 



My late and much-esteemed friend Mr. Hudson, 

 author-pof the <* Flora Anglica," was of this 

 opinion, till I convinced him of the contrary by 

 some experiments made at Nutwell, near Exeter, 

 the seat of the late Sir Francis Drake, a gentleman 



I 



