218 VEGETABLE PARASITES. 



that lie on the bottom in a solution of sugar. Berg thinks that 

 they also belong to the thrush-fungus. No particular formation 

 of aphthae was observed in the case of scabs which were preserved 

 in pure water at a temperature of 30 35 C. (86 95 Fahr.), 

 but they were very numerous Tjrhen the scabs were preserved in 

 the mixture of arrow-root. A small cloud was perceived after 

 forty-eight hours, consisting of the fungus, but possessing only 

 few and short stalks. The process proceeded most luxuriantly at 

 the same temperature in a solution of sugar, the result being the 

 formation of a white mouldy membrane or layer on the surface of 

 the liquid, which is said to have been produced by small patches 

 of the aphthae-fungus which floated in the liquid, whilst at the 

 same time a gas was emitted from the liquid employed. The same 

 phenomena were observed in a solution of cane-sugar mixed with 

 albumen, in which fungi grew for ten days. Solutions of milk- 

 sugar likewise exhibited a mouldy membrane, with similar spo- 

 ridia to those of the aphthae-fungus. 



Berg next examined the stems and spores of isolated fresh 

 thrush- fungi, after having carefully removed all organic portions 

 of the epithelium, &c. He did not succeed in tracing the growth 

 of these fungi in distilled water at a temperature of 30 35 C. 

 (86 95 Fahr.), but he noticed a slow growth of the fungous 

 elements in a hermetically sealed-up solution of sugar at 15 C. 

 (59 Fahr.), and a more rapid one in solutions of sugar con- 

 taining albumen, the growth being, however, slower in the latter 

 case at a temperature of 15 C. (59 Fahr.) 



Experiments on the thrush by Berg. 



Berg took scabs of aphthae, and mixed concentrated solutions 

 of borax, soda, alum, and corrosive sublimate (about one twentieth 

 part) with a solution of cane-sugar containing the scabs. All 

 these compounds seemed to impede their growth. The solutions 

 to which borax or soda had been added exhibited gradually a less 

 alkaline reaction, and on exposing the scabs perhaps longer than 

 for a period of six days, another result might probably be 

 obtained. The same took place when eight grains of nitrate of 

 silver were mixed with one ounce of water and nineteen twen- 

 tieths of cane-sugar and scabs of aphthae. I cannot see the use 

 of these experiments, as the aphthae-fungi exist here under different 

 circumstances to what they do naturally. If therapeutics are to be 



