1923] 



LEHMAN — POD AND STEM BLIGHT OF SOYBEAN 125 



strains and possibly they indicate an abotrive attempt on the 

 part of the former to form perithecia. 



The discovery of the perfect stage of a plant pathogenic 

 fungus in culture before the same has been found developing 

 naturally on the host is not without precedent. In 1892, Atkin- 

 son ( '92) described Gloeosporium cingulatum which he had isolated 

 from a diseased stem of privet obtained in New York. No 

 ascogenous stage was present on the host tissue. However, 

 bodies resembling pycnidia or perithecia, but devoid of spores, 

 developed in certain of the cultures. Later Stoneman ('98) 

 obtained perithecia and mature asci in cultures of the same 

 organism isolated from privet sent from Kansas. Still later, 

 Shear and Wood ('13) found fertile perithecia on leaves and 

 stems of privet obtained from Nova Scotia. Shear and Wood 

 ('07) grew both conidial and ascogenous stages of anthracnose 

 fungi from 8 different hosts as follows : Gloeosporium rufomaculans 

 from grape, G. fructigenum from apple, an unnamed Gloeosporium 

 from cranberry, G. elasticae from rubber plant, an unreported 

 form from locust, another from Ginkgo biloba, C ollelotrichum 

 Gossypii from cotton, and C. lindemuthianum from bean. Of 

 the 8 cases, the perithecial stage of the form from apple only 

 had been found previously under natural conditions upon its 

 host plant. The ascogenous stage of the form from rubber plant 

 was found during the progress of the work reported. Later, 

 Edgerton ('09) found perithecia of the form from cotton on 

 diseased bolls in Louisiana, and named the fungus Glomerella 

 Gossypii. In a subsequent paper, Shear and Wood ('13) gave 



the results of more extensive studies in which they determined 

 the life histories of forms of Glomerella cingulata from 36 different 

 host plants. In 17 cases perithecia were produced in pure 

 cultures, and in the remaining 19 cases they developed on the 

 host either in a moist chamber or under natural conditions. 

 In 9 of the 36 cases they were present both in culture and on the 

 host. In 1920, the writer (Wolf and Lehman, '20) found peri- 

 thecia in cultures isolated from diseased soybean pods which 

 bore numerous Colletotrichum-like acervuli. Dr. Shear, to whom 

 cultures were submitted, stated that he believed the perithecia 

 to be those of Glomerella cingulata. No perithecia were found 



