r 



223 



contaîning sterilised water, and consequently they spread over the 

 surface. With a looped platinum wire a drop of Iiquid was talcen 

 from the surface and dropped into one of the flasks. One must 

 admit, that in this way we introduce a more or less equal number 

 of conidla mto each vessel. There was always an equal development 

 m ail the flasks; if there was a différence, it was only visible during 

 the first few days and was very slight. 



The cultures were kept in a room in which the température was 

 kept constant by automatically regulated electric heaters at 22' (later 

 20"). Oscillations of more than 0.2 were very rare. By keeping 

 flat open zinc basins filled with water in the room the humidity 

 of the air was also kept constant. As the room had no Windows, the 

 cultures were in the dark, except during the times, when the ob- 

 servations were made. I never found any influence of the electnc 

 light on the cultures. There were no gaspipes in the room. 



Germination as a rule had proceeded far enough after two or 

 three days, to enable me to begin the experiments. During the 

 first week two cultures were taken every day and during the second 

 week every other day. After that, cultures were only taken every 

 third or fourth day. The cultures were treated as follows: the 

 culture solutions were filtered off. In one case the mycélium was 

 filtered through a dried and weighed filterpaper and was dried in a 

 dessiccator afterwards until the weight was constant. In this way 

 we are able to find accurately how much fungus had been devel- 

 oped. 



The other mycélium was thoroughly washed to remove ail the 

 adhering culture solution and diastase. It was then rubbed down 

 with infusonal earth and extracted with culture solution which had 

 been boiled, so as to destroy ail the possible enzymes in it. Some- 

 times 75 ce. water were used for the extraction. After standing an 

 hour, the mixture was filtered and the iiltrate was tested for dias- 

 tase. The culture solution of the first jar was also tested in the 

 same way. Often a third culture was used and the mean of the 

 results taken. 



To test the concentration of the diastase, the following procédure 



