CTOW 



394 BOTANICAL GAZETTE [june 



■ 



At first the colony on sugar media was covered with an erect "rowth 

 of mycelium which became pink colored with the spores. But after 

 it had been grown for several months on artificial media, the aerial 

 mycelium lost to some extent its erect character, becoming denser 

 and more floccose. Furthermore, the aerial mycehum lo^t entirely 

 its pinli character due to the formation of spores. The same varia- 

 tion also occurred with the collection from tomato. But it is interest- 

 mg to note that two collections from raspberry stems^ and another 

 one from apple, which were identical at first with the two forms above, 



held their characters as long as they were cultivated— in some cases 

 over a year. 



The forms from quince and red raspberry, after they had been 

 under culture for some time, underwent slight changes in the color of 

 the agar and the aerial mycelium. In fact, nearly every culture 

 changed its character in time. 



An attempt was made to change the characters of a form collected 

 on apples in the north, which had appeared to remain constant, by 



'ng on different media for several months. The following media 

 were used: potato agar, potato agar + io per cent, of glucose, potato 

 agar + copper sulfate (i : 100,000), potato agar with a drop of lactic 

 acid in each tube, and Elfving's nutrient solution. Transfers were 

 made every ten days to three weeks into fresh tubes of the same 

 medium; so that at the end of the experiment the fungus in each 

 tube had grown for several months, with many generations on the 

 same medium. At the end of three months these cultures were all 

 brought back on plates of potato and glucose agar, and at first the 

 results were striking. For about a week the growth in this medium 

 from the different tubes was quite distinct; however, after two weeks 

 or more these differences graduallv disappeared, and the old cultures 

 looked more ahke. 



After the fungus had been growing for about four months on the 

 ditlerent media, it was again brought back to the same potato and 

 glucose agar, and the results were more striking than in the first case. 

 iJitterences appeared which did not disappear with the age of the 



tyne do ^nT^T'"''''^ l"" Gloeosporium on raspberry stems under the discussion of this 



latter do./ ''! "" *° '°"'°'°'' raspberry anthracnose, Gloeosporium venetum. The 

 latter does not appear to belong to the Glomerella tj-pe. 



