SYMPTOMS OF DISEASE (SYMPTOMATOLOGY) 



345 



2. Shot-holes (Fig. 135). — The perforations of leaves and the forma- 

 tion of what are called shot-holes illustrate another form of fungous 

 attack, where circular patches of dead tissue killed by the fungus drop 

 out leaving a hole. The Enghsh morello cherry trees in some sections 

 of our country have been killed during the past few years by this " shot- 



FlG. 135. — Shot-hole disease of the plum due to Cylindrosporium 



Heald, F. D., Bull. 135 {Sci. Ser. 14), Univ. of Tex., Nov. 15, 1909.) 



{.After 



hole" disease. When the funguses belonging to the genera Cercospora 

 and Phyllostida attack the leaves of Virginia creeper perforations may 

 be formed. 



3. Wilting. — Wilting in general is due to the lack of sufficient water 

 to supply that lost by transpiration, for wherever the amount of water 



