Chemistry. — "Amygdalin as nutriment Jor Fusarium." By Dr. 

 H. I. Waterman. (Communicated by Prof. Dr. J. Böesekkn). 



(Communicated in tlie meeting of May 26, 1917). 



A solution of amygdalin in tapwater which at the same time con- 

 tained inorganic salts as NH^NOj, KH^PO^, and MgSO^ remained in 

 the laboratory for some time at the ordinary temperature. After 18 

 days spontaneous infection was observed. On the Hquid a white 

 flocky mass of mycelium had appeared, under which a rose-coloured 

 underground. 



From this mycelium somethiug was transferred to a plate of malt 

 agar and cultivated at the ordinary temperature. After 24 hours 

 some growth could already be observed, after 2 X 24 hours a flocky 

 mycelium had been formed, whilst 24 hours later a very vigorous 

 development was observed. A white tlocky mass of mycelium was 

 visible then ; the plate had obtained on some spots a yellow and on 

 other spots a red colour. The red colour was especially concentrated 

 in those places of the nutrient plate which in transferring had been 

 jn contact with the platinum-wire. 



The following day (after 4 X 24 hours) the whole glass-box was 

 filled up with white mycelium. 



The microscopy of the thus isolated species of mould and especially 

 the presence of sickle-shaped spores divided into several cells pointed 

 to Fusarium. 



This species of Fusarium developed well on nutrient soils of the 

 composition : tapwater whether or not coagulated with agar and 

 containing 2»/, amygdalin, 0,157„ NH,N03. 0.157„ KH,PO„ 0.10% 

 magnesiumsulfate (crystallised). From the means of isolation this 

 could be expected. 



On amygdalin-agar Fusarium developed as white flocky mycelium, 

 whils^t this nutrient plate was for the greater part coloured yellow. 



Especially on this nutrient soil the formation of sickle-shaped 

 spores came to the front. 



Some days later the yellow colour had for the greater part become 

 red, whilst the mycelium had shrivelled. Besides, on malt agar this 

 shrivelling after a prolonged cultixation was observed too. 



The formed red colour of the amygdalin plate did not dissolve 



13 



Proceedings Royal Acad Amsterdam. Vol. XX. 



