54 maine agricultural experiment station. iqio. 



Fermentation Tubes. 

 The Endomyces from apple has been grown in fermentation 

 tubes which were filled with 2 per cent dextrose, saccharose, 

 lactose, and mannite broths, and with 5 per cent glycerine broth. 

 In dextrose, saccharose, and glycerine broths the fungus grew 

 well in the open ends of the tubes but did not grow in the closed 

 ends. In lactose and mannite broths, the growth was poor and 

 was confined to the open ends of the tubes. No gas was pro- 

 duced in any of these fermentation tubes. 



Relation of Temperature to Growth. 

 The growth of the fungus on a number of culture media at 

 20 degrees C. has been given under the head of cultural char- 

 acters. In order to determine the effect of lower temperatures, 

 2 tubes each of prune decoction, bean agar, potato agar, po'.ato, 

 beet, carrot and turnip cylinders in each case were inoculated 

 and kept at temperatures of i5°-i6° C, I2°-I3° C, 8° C. and at 

 5° C. At i5°-i6° C. and at I2°-I3° C, there was a slow growth 

 but not so good in either case as at 20° C. At 8° C. and at 

 5° C, there was no growth which could be noted at the end 

 of one week while in check tubes at 20° C, the fungus had 

 spread over the entire surface of the slants. When the tubes 

 which had been kept at 5° C, and at 8° C. were placed at a tem- 

 perature of 20° C. growth took place readily. 



Thermal Death Point. 

 Cultures of the fungus two days old in thin walled test tubes 

 each containing 10 c. c. of 2 per cent dextrose broth made acid 

 to +10 were used. A method of heating the cultures very sim- 

 ilar to that described by Smith (14) was used. Tubes were 

 heated for 10 minutes at each degree from 46° C. to 53° C. 

 Transfers were made to other tubes of 2 per cent dextrose 

 broth. There was good growth from all tubes up to 50° C. At 

 51° C. and at 52° C, the growth came up very slowly and at 

 first it seemed that the thermal death point was between 50° C. 

 and 51° C. but since growth took place at 51° C. and at 52° C. 

 after a few days and no growth took place from tubes at ^^° C. 

 it seems that some place between 52° C. and 53° C. should be 

 regarded at the thermal death point. 



Growth from Old Cultures. 

 In order to determine the length of time which the fungus 

 M'ould retain its vitality in cultures, transfers were made from 



