DESCRIPTION OF PLATE X. 



Melon wilt. Result of soil inoculations ivith the external fungus. Hothouse experi- 

 ment. Washington, D. C. Photographed June 10, 1895. The fungus used for infec- 

 tion was derived from a single, large, lunulate, several-septate spore, taken from the 

 surface of a plant killed by the internal fungus. When photographed there were no 

 conidia beds on the surface of these wilted plants, but in each case the internal 

 fungus was found plugging the vessels of the taproot; the internal conidia were 

 elliptical or bluntly i)ointed, straight or slightly curved, nou-septate, and 8 to 20 by 

 3.5 to t //. On June 8 the plant at the right was as healthy looking as its companion, 

 but the plant in the middle pot and at the extreme left were already wilted. The 

 three healthy vines afterwards contracted the disease. 



