1923] 



LEHMAN — POD AND STEM BLIGHT OF SOYBEAN 



121 



septate. When germination of spores immersed in the w* 

 occurs, the germ tubes soon develop septa and the cells si 

 and branch in an irregular and curious manner. 



Stylospores are found infrequently in pycnidia of the soyb 



pod- and stem-blight fun 



They are long, slender, hyaline 



curved or hooked cells which may or may not be found in the 



same pycnidium with pycnospor* 

 of the strains of the fungus isolat- 

 ed from diseased soybeans have 

 not formed stylospores in culture. 

 However, they were found once 

 in a few pycnidia of strain 14 and 

 occur regularly in cultures of 

 strain 17. The latter produces 



The greater number 



perith 



gularly in culture, 



but pycnospores are less abun 

 dant and stvlospores 



more 



merous than in imperfect 



Stylospores 

 found under 

 on host tissu 



are occasionally 

 natural conditions 

 , All attempts to 



germinate them have been 

 successful. 



Fig. 4. Stylospores of soybean fungus 



PERITHECIA 



The ascogenous stage of the soybean fungus has never been 

 found in the field. Material wintered out of doors during 2 

 seasons did not develop perithecia nor has repeated examination 

 of diseased stems and pods picked up in soybean fields at various 

 times during winter and spring revealed any perfect stage. 

 Apparently the soybean fungus seldom, if ever, forms asci and 

 ascospores under such field conditions as exist at Raleigh, North 

 Carolina. Up to the present time perithecia have been found 



only in culture. 



Within the extended period during which this disease has 

 been under observation, the causal organism has been repeatedly 

 isolated from diseased seeds, pods, and stems. Most of these 

 strains have been kept in culture for 6 weeks or more, while a 



