86 



More recently he made an investigation of Sporod'mia grandis 1 ), and came 

 to the conclusion, that by changing the nature of substrata one or other 

 kind of sexual organs was artificially produced according to the author's 

 will. Further, Lendner 2 ) studied Mucoreae with reference to light and 

 substratum. Ray*) observed that Sterigmaiocystis alba produced only pencils 

 of unbranched sterigmata instead of ordinary branched ones, when it was 

 sown In a sugar-solution, while that cultivated in a salt-solution showed 

 merely sterile conidia-bearing hyphae. 



For my part I have examined by a series of experiments how the 

 conidia-formation of Aspergillus niger is influenced by chemical nature 

 and concentration-grade of various inorganic salts. The greater part of 

 this work has not yet been completed, so that I will here give some of the 

 results as only a preliminary note. 



To begin with, I prepared a liquid-medium, which afforded to my 

 fungus an abundant nourishment and the most complete development. 

 I used it as a fundamental medium throughout my experiments, adding to 

 it every time certain quantities of inorganic salts. For the medium in 

 question I preferred the solution proposed by Prof. Miyosh[ 4 ). For con- 

 venience sake, I will here give its composition : 



Distilled water 50 ccm 



Concentrated boiled solution of Allium-bulhs 25 „ 



Soja .20 „ 



Cane-sugar 5 g 



The inorganic salts which I used for my experiments were those of 

 potassium, sodium, ammonium and magnesium. On the examination of 

 my cultures I always compared them with the control- culture, which I made 

 simultaneously with the other cultures. During the experiments my atten- 

 tion was especially turned to the development -period of conidia-bearing 

 hyphae as well as to the colouring period of conidia. I also observed the 

 length of conidia-bearing hyphae, the thickness of their cell-walls, the size 

 of conidia-fruits and the diameter of conidia themselves. As a matter of 

 fact the development of mycelium and reproductive organs is greatly in- 



*) G. Klebs. Zur Physiologie cler Fortpflanzung einiger Pike. Jalirb. f. wiss. Bot. 

 1898. Bd. XXXII, Heft 1. S." 41. 



2 ) A. Lendner. Pes influences combiees de la lumiere et du substratum sur la 

 developpement des Champignons. Ann. d. Se. nat. Bot. 1897. Ser. VIII, T. 3. p. 1-64. 



3 ) J. Ray. Variations des champignons inferieurs sous l'influence du milieu. Revue 

 generate de Botanique. 1897. T. 9. p. 301. 



*) M. Miyoshi. Durchbohrung der Membranen durch Pilzfaden. Jahrb. f. w|ss. Bot. 

 1895. Bd. XXVIII, Heft 2. S. 272. 



