FUNGOID DISEASES OF FOTATOES 93 



raised meal-like markings, and are sometimes mis- 

 taken for disease spots. The potatoes are, however, 

 perfectly healthy. 



{e) Rttst'like specks or streaks are sometimes found 

 inside otherwise sound tubers, hence the names 

 *' streak," ''sprain". The cause is not definitely 

 known. No fungus has as yet been found within ; it 

 does not spread in the "pies," and is apparently 

 not contagious. Weather and soil conditions are 

 thought to be responsible, but further research may 

 reveal the presence of some organism within the 

 tissues. 



Note. — For insect pests attacking this group see " Farm and 

 Garden Insect Pests," by Somerville. M.M. & Co. 



