Feb. i, 1921 



Variations in Colletotrichum gloeosporioides 



727 



lowing manner: A dilute suspension of the spores taken from green 

 bean plugs was made in sterilized tap water, and a drop of the suspension 

 was placed on a microscope slide and covered with a cover glass. It was 

 necessary to make the measurements quickly, because the spores did not 

 remain quiet for any length of time. The image of the spore was thrown 

 on drawing paper by means of the camera lucida, and the length and 

 width were quickly marked with a pencil. The microscope was so ad- 

 justed that 1 micron on the micrometer scale in the eyepiece was equal 

 to 1 millimeter on the paper. Therefore, after the length and width 

 were indicated on the paper the spore size could be quickly ascertained 

 by means of a millimeter rule. 



Table II.- 



-Variation in spore length in the different strains of Colletotrichum gloeos- 

 porioides 



It was soon determined that each strain had a certain range of vari- 

 ability in its spore length and width (see Table II). While there were 



