228 



used. I can only say that I got my stock from a pure culture, which 

 I obtained from the Phytopathological Laboratory "Wlllle Com- 

 melin Scholten" in Baarn (Holland); from this stock my first cul- 

 tures were made. 



Oneofthemam reasons, why Brenner succeeded in getting so 

 many races, is the higfi température, at which he grew his fungi, 

 1. e. 35^. At this high température many complications appear, 

 which I never noticed when working at 22" and 20", e. g. the forma- 

 tion of starch in the hyphae. Boas also has warned us, that Asper- 

 gillus nt^er shows many peculanties when cultivated at high tem- 

 pératures. 



In this connection I may mention, that there is another considé- 

 ration of very great importance, namely with which conidia a given 

 séries is inoculated. I sometimes took two séries of experiments 

 and inoculated one of them with conidia from a culture, in which 

 the same nutritive liquid was used, whilst the second séries was 

 inoculated with conidia from a différent culture solution. In ail 

 such cases great différences were observed between the two séries : 

 dry weight, diastase production, habitus, formation of conidia, ail 

 thèse points differed in fungi, derived from conidia of différent 

 origin. As yet I hâve not found any fixed rules for thèse changes, 

 but I hope to return to this question farther on. I am however 

 able to point out some very remarkable instances now. The tables 

 1 A aryj I B give the results of an investigation of diastase forma- 

 tion by two séries, both of which were cultivated on a 5% glucose 

 solution. The conidia of the first séries were taken from a culture 

 on 5"o glucose, I therefore call this séries G G. The other séries 

 was inoculated with conidia from a culture on 0.5% starch, hence 

 A G. Fig. 10 gives the reader an idea of the production of dias- 

 tase in two séries, the first of which was grown on 0.5% starch 

 with conidia from a culture solution of the same composition 

 (A A), the second also on 0.5% starch, but the conidia came from 

 a culture solution containing 5% glucose (G A). 



In ail thèse cases the conidia were derived from well developed 

 cultures, which were never more than three or four weeks old. We 



