34 



mon point, down the trunk, and around the trunk. When 

 these portions of the disease \vhich go around the trunk meet on 

 the other side, we have a branch or a trunk which we speak of as 

 girdled. Now a girdled branch, or a girdled twig, or a girdled 

 trunk, means the early death of all parts of the tree beyond the 

 girdled area. If it is a twig, it means the death of the twig be- 

 yond the girdled area. If it is the trunk, it means the death of 

 the whole tree at once, or soon after the girdling is completed; 

 not immediately, as a rule. Now I want to call your attention to 

 some of the obvious effects of this girdling upon the foliage of 

 the tree. When you are looking for this disease during the sea- 

 son of foliage, it can be detected oftentimes at a great distance. 

 I have myself detected diseased trees more than a mile away, or 

 trees supposed to be diseased, by the characteristics which I want 

 to call your attention to now. To be sure, you must bear in mind 

 that the coloration of the leaves to which I am going to call your 

 attention can at times be brought about by other tilings than this 

 disease; but we have in the coloration of the leaves, as we gener- 

 ally say, the "danger signal" which suggests where to look for I lie 

 disease; for, if the disease has been going on very long, for a few 

 months, or weeks even, in certain places, we shall get some of 

 these discolored leaves as the result of the girdling of some one 

 or more of the twigs or branches. I have shown here a somewhat 

 normal chestnut leaf. It is a little-broader than the normal leaf; 

 this is intended to represent not, perhaps, a perfectly typical 

 chestnut leaf, because we have on the margin a little paler green 

 tliiin in the portion in the centre. The pale green in the margin 

 of every leaf at times, is one of the first symptoms of discolora- 

 tion. It becomes a little pale. First of all, perhaps, the leaf 

 wilts a little, if you notice it carefully, and if this paleness of the 

 leaves is extended over the leaves of a whole branch, the effect as 

 a whole is quite noticeable. 



No. 16. Here is a greenhouse plant which has been inocnlaicd 

 with the disease. At the left we find some of the normal clirsl 

 nut leaves; at the right a branch which had been inociilaiod ami 

 has been girdled way down here. (Indicating). Now I do not 

 know about that particular specimen, but, if we were looking for 

 the disease on such a specimen as that, we should never look up 

 here for it, that is, not primarily. What is causing the trouble 



