190 Ebfobt of the Boxajs'ist of thq 



EXPLANATION OF PLATE XXV. 



Fig. 1. — Peach twigs hearing the knots on which Helminthosporium 

 sjpores are found. 



Fig. 2. — A peach affected with hrown spot caused hy Helmintho- 

 sporium carpophilum Lev. 



Fig. 3. — Two Helminthosporium spores direct from a peach twig 

 killed hy the fungus. They represent the prevailing 

 forms. 



Fig. 4r. — Two spores of H. carpophilum from peach fruit. They 

 represent the prevailing forms found on the fruit. 



Fig. 5. — Five spores rt/ Helminthosporium grown in a pure culture 

 ohtained from the knots shown in Fig. 1. 



Fig. 6. — A spore from the same culture germinated in sugar solu- 

 tion. The normal method of germination. 



Fig. 7. — Three spores from the same culture germinated in dis- 

 tilled water. Ahnormal germination. 



Fig. 8. — Mycelium and four newly formed spores grown in sugar 

 solution. 



Figures 3-8 were drawn with the aid of a, cajnera-lucida and 

 all to the same scale. 



