490 



VISEASES OF ECONOMIC PLANTS 



16,000,000 in 6 or 8 hours under the most favorable conditions) 

 that notwithstanding their minuteness they are formidable foes. 

 They are, of course, invisible to the naked eye except in masses 

 of countless numbers. 



Fio. 214. — Bacillus subtiliB. Swarming rods with numerous fine Sagella. A, after 

 7} hrs,; B, after 8J bra., with fully developed flagella. (After A. Tiacher.) 



English Equivalents of Metric Units •> 



1 mm. 0.0394 inch, or approximately ^ inch 

 1 cm. 0.3937 inch, or approximately ^ inch 

 1 dm. 3.9370 inches, or approximately 4 inches 

 1 m. 39.37 inches, or approximately 1 yard 



