THE FUNGUS fAUSINli ANTHHACNOSE. 33 



cia, but no asci were ever found. Transfers made of germinating 

 ascosjiores from such poured plates to flasks of sterilized corn meal 

 produced ascogenous perithecia in abundance in about ten to twelve 

 daj^s. In the case of one culture made from a diseased berry, very 

 few conidia were ever formed, but an abundance of the ascocrenous 

 form Avas ])resent after eighteen days. A\'e have not as yet succeeded 

 in growing the ascogenous form in pure cultures from single conidia. 

 Little o])i)()rtunity, however, has been given for making such cultures 

 from the ascus-bearing form, on account of the few conidia produced 

 by it. Besides beef agar and corn meal, the fungus has been grown 

 upon cranberry agar and corn meal, and also ujwn potato cylinders. 

 Although the fungus appears to grow best on corn meal or cranberry 

 agar and corn meal, there is nothing to indicate that the culture 

 medium is the determining factor in the ])rofluction of the ascogenous 

 stage of the fungus. As in the case of the scald fungus. Oiik/iuu'dia 

 vaccina, the important factor seems to be some particular potentiality 

 of the mycelium or spore from which the culture is made. 



Factors cletermining the production of the ascogenous fructifica- 

 tion. — Previous successful attempts of the Avriter and others to pro- 

 duce asci in various forms of Gloeosporium have indicated that there 

 is a much more important factor involved than the culture medium or 

 conditions of light, temperature, and moisture. Whether the near- 

 ness or remoteness of origin of the conidia from an ascogenous form 

 is of importance has not yet been satisfactorily determined. The 

 successful cultures made by Miss Stoneman *■' Avere from conidia 

 taken from acervuli produced upon the diti'erent hosts of the species 

 studied. In such cases, of course, there is no means of determining 

 the ancestry of the conidia used. 



Relationship of the fungus. — The ascogenous forms of the numer- 

 ous anthracnoses known have very rarely been recognized or reported 

 as occurring under natural conditions. It is probable, however, that 

 some of the jDyrenomycetous fungi which have been described under 

 the genera Physalospora or Phomatospora, or perhaps under other 

 closely related genera, are really the ascogenous forms of species 

 of Gloeosporium. The very close relationship of many of the species 

 described under these genera and the want of any very striking or 

 peculiar characteristics of the known ascogenous forms of Gloeospo- 

 rium make it difficult to determine wath certainty from purely mor- 

 phological characters the generic identity of these organisms. The 

 name Glomerella has been proposed for these fungi by Spaulding 

 and von Schrenk.^^ This name, however, may have to be abandoned 

 if it can be demonstrated that ascogenous forms heretofore described 

 under an older valid generic name are really stages in the develop- 

 ment of congeneric species. The question of specific distinctions in 



110 



