International Review of Educational Cinematography (Jan-Dec 1931)

— 1006 — the organism is dried, drowned, or otherwise incommoded according to circumstances. The blue, green and black moulds which occur on cheese, bread, fruit, etc., often pass through a complete life-cycle of spore to spore-production in three or four days. Obviously here was a remarkably attractive type for experiments. Pear juice containing 5 % gelatine was neutralised with ammonia, clarified, sterilised and spread upon culture plates. On this nutrient the three types of moulds could be cultivated with the greatest ease ; nevertheless, nearly a year's work was required before a series of pictures sufficiently complete for public presentation could be obtained. The worst trouble was, however, still in store. Other similar subjects being put in hand it was found that the airborne spores of the moulds persisted in putting in an appearance in practically every culture. Books, papers, clothes, instruments all supplied hiding places for the pests, and liberated them at the slightest provocation. Finally a complete overhaul and redecoration of the room was decided to be the only remedy. Before the walls were thoroughly dry a considerable area of green began to superimpose itself upon the pink. The happy little mould had discovered quite a good food supply in the size of the distemper.