34 



moil point, down Uk; Iniiik, and aronnd llic Uiink. NVIiun 

 Hicso jtoi'tions of (lie disease wliieli <;() aronml (lie (ruiik meet on 

 (lie ollici- side, W(^ have a hraiicli or a (i-uiik w liicli we speak of as 

 j»irdled. Now a i;ii'dled braiicli, oi- a i;ii'dled twij», or a girdled 

 trniik, ineans (lie early death of all i)ai'(s of the tree beyond the 

 girdled are;i. If it is a tAvig, it nicjiiis (he death of (he twig be- 

 yond (he girdled area. If it is (he (riink, i( means (he dea(li of 

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

 not immediately, as a rnle. Now I w;nit to call yonr attention (o 

 some of the obvions eti'ects of this girdling npon the foliage of 

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

 son (»f foliage, it can be detected oftentimes at a great distance. 

 T have myself detected diseased trees more than a mile aAvay, or 

 tiH*es sui)])Osed to be diseased, by the characteristics which I wiint 

 to call your attention to now. To be sure, 3^ou 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 things than (his 

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

 ally say, the "danger signal'' which suggests where to look for (he 

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

 iiiouths, or weeks even, in certain places, Ave shall get some of 

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

 oi' more of the tAvigs or branches. I have shown here a someAvhat 

 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 Ave have on the margin a Ii(tle paler green 

 than 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 

 Avilts 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 Avhich has been inoculated 

 Avith the disease. At the left aa'c find some of the normal chest- 

 nut leaves; at the right a branch Avhich had been inoculated and 

 has been girdled Avay doAvn here. (Indicating). Now I do not 

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

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

 here foMt; that is, not primarily. What is causing the trouble 



