DESCRIPTTOX (>F PLATE I. 



rnrl-iiifcstcil pcacli sliout from BifTff*, Cal. Tx\avps of tliis cliaractcr arc lui'lly 

 intVst(.'<l with ICxumcus defonnaiix. The gri'utly broadeiietl and (list( irtcil Icavos, which 

 arc characteristic of this disease, are shown, and the whitentn], spore-covered surface 

 of some of the more elevated portions of the upper surface may be distinguished. 

 The petioles of the affected leaves are greatly enlarged, the branch is nnich bent and 

 distorted, and the internodes of the disi-ased portion of tlie branch are greatly 

 shortened. A branch thus badly diseased is apt to die during the year unless con- 

 ditions for growth are very favorable. It is in shoots of this character that the 

 mycelium occurs in greatest abundance, but the hyphre have been seen to spread 

 only a shoit distance beyond the i)arts showing the hypertrophy. (Compare with 

 ris. V and VI.) 



