268 



Mycological Bulletin Nos. f<7 and bS 



[Vol. IV 



mushrooms are being grown, one will frequently find that an injur}- 

 in. a young mushrcom is rapidly healed by a growth of hyphae from 

 the edges of the injured area. The same thing had been noted in the 

 open in the case of pufifballs. In many instances, moreover, pure cultures 

 of furgi in other groups have been obtained by the use of small bits of 

 a sclerotial mass of tissue. Accordingly, a young sporophore of Agariciis 

 canipcstris was obtained, and after breaking it open longitudinally a num- 

 ber of pieces of tissue from within were carefully removed with a sterile 

 scalpel to a sterile Petri dish. A number of cultures were then made by 

 this tissue-culture method on a variety of nutrient media, such as beau 

 pods, manure, leaf mold, etc. From this and from numerous other similar 

 tests it was ascertained that when the mushrooms, from which the nodules 

 of tissue are taken, are young and healthy, there is seldom an instance 

 in which growth does not result.- It was easily shown that- failure to 

 grow was generally due to the advanced age of the mushroom used, to 

 an unfavorable medium, or to -bacterial contamination. 



The first successful pure cultures were made by this method during 

 the early spring of 1902 from mushrooms grown indoors. During the 

 following summer, or as other fleshy fungi appeared in the open, cultures 

 were made from other forms in order to determine the general applicability 

 of the method. The experiments were successful in most cases, although 

 it was found almost impossible to obtain certain species of fungi in a 

 condition young enough to be free from bacterial infestation. In general, 

 the method .^eemed to commend itself strongly as a means of procuring 



I'"ig. 207. 'I'hc Mclliofl of Making I'mc Cultures, Slipvving tin.- .Viiparatus ami 

 Materials. I'rcni liulUtin Nu. S.'), ]',. M. Du^gar, I'.uriaii of Plant In- 

 dustry, U. S. i)t|iartnH nt nf .\>.'rici'.lturc.- 



