CH. XII.] 



PINE-BLISTER. 



257 



developed from a mycelium in the tissues of the 

 leaf. I must employ these technical terms, but 

 will explain them more in detail shortly : the 



FIG. 37. To the left is a pair of leaves of the Scotch pine, with the blister-like 

 JEcidia. a, of Peridertnhtnt Pint (var. acicola) projecting from their tissues : 

 these blisters are orange-yellow in colour, and contain spores, as shjwn in Fig. 38. 

 Between the blisters are the minute tpermofonia, b. To the right is a small 

 branch, killed at a a a by Peruierntium Pint (var. corticola), the blister-like 

 yellow ^Ecidia of the fungus being very conspicuous. (Reduced, after Hartig.) 



point to be attended to for the moment is that 

 this fungus in the leaf has long been known 

 under the name of Peridermium Pint (var. acicola, 



S 



