WILT DISEASE OF COITON, WATERMl-LON, AND COWPEA. 



{2ieoeo8ino8pora uov. geu.) 



The fimgus here described has been under uearly continuous obser- 

 vation for five years. A number of points in its life-history remain to 

 be worked out, but as a year or two must necessarily elapse before the 

 investigation is completed, it is thought best to put the main facts on 

 record at this time, particularly as more material has been accumulated 

 than is usually considered ample for the description of a genus or 

 species. 



This material has been accumulating during so long a period that it 

 now amounts to a very considerable mass of correspondence, notes, 

 slides, photographs, drawings, etc., and only a condensed account is 

 here possible. The facts are set forth in as few words as possible, but 

 each one depends on more than a single observation or experiment, 

 and often statements which occupy only a word or two or a line or two 

 are based on scores of observations. Whenever the writer has been in 

 doubt, and that was often, he has repeated the experiment or made 

 additional observations. The long delay in publication is due to the 

 fact that he was disappointed at the result of the cross-inoculations 

 and over certain other failures which are mentioned in their proper 

 place. 



DESCRIPTION OF THE FUNGUS. 



Asconiycetous s/rt/ye.— Perithecia on the roots (PI. I, 1) more rarely on 

 the parts above ground, superficial, resting on a slight subiculum, some- 

 times developing in the earth near the roots, or underneath the loose 

 bark of the host plant, or deep in cavities or rifts of the decomposing 

 root or stem, but always free from the tissues of the host and not borne 

 on any distinct stroma,^ infrequent or numerous, scattered or several 

 to many together; ovate, slightly higher than broad, of quite variable 

 size, ranging from 210 to 400 /.i in height by 150 to 328 ju in diameter, 

 mostly 250 to 350 by 200 to 300 //.^ Peridium about 20 /< thick, coral 

 red to vermilion red, or in water under a cover glass, of a uniform 

 purplish red, when fully ripe becoming orange vermilion (Ridgway's 



»Wlien cultivated ou slices of cooked potato the peritliecia are usually developed 

 from a more or less elevated, tough (fleshy), grayish-white stromatic surface of quite 

 different appearance from the ordinary mycelium. 



" One hundred and eleven measurements. 



7 



