IMPLICATIONS 27 



culture to another, contaminate all of them. jVIites cannot be 

 excluded no matter how tight the stoppers are. To guard against 

 infestation the strictest vigilance and the most stringent sanitary 

 measures must be employed at all times. Before infestation is 

 widespread, fumigation with carbon tetrachloride or pyridine 

 can be effectively employed. These chemicals are allowed to 

 evaporate from shallow dishes placed in the culture cabinets. 

 After 3 or 4 days a second fumigation is necessary because 

 the egg stage and an encysted stage of the young mite are more 

 resistant to vapors of these chemicals than are adult mites. All 

 cultures should be transferred early after fumigation. 



IMPLICATIONS 



Certain principles underlie the techniques of isolation and cul- 

 tivation of fungi. Following routine directions and procedures 

 may cause failure to isolate or to grow a specific fungus arti- 

 ficially. Failure may be attributable to use of the improper kind 

 of substrate. Fungi should be expected to respond in a most 

 nearly normal manner if food and environmental influences ap- 

 proximate those that they encounter in their natural habitat. It 

 is of course impossible in many studies to duplicate these condi- 

 tions artificially, but a knowledge of these facts about a given 

 fungus may prevent loss of time in attempts to isolate it and mis- 

 interpretation of results of its responses when grow^n in culture. 

 It follows, therefore, that the fungus in culture may be quite 

 pathologic and that a study of its physiology in culture may 

 in reality be a study of its pathology. 



LITERATURE CITED 



Bach, W. J., and F. A. Wolf, "The isolation of the fungus that causes 

 citrus melanose and the pathological anatomy of the host," /. Agr. 

 Research, 57; 243-252, 1928. 



Badcock, E. C, "Methods for obtaining fructifications of wood-rotting 

 fungi in culture," Trails. Brit. Mycol. Soc, 26: 127-132, 1943. 



Barber, M. A., "The pipette method in the isolation of single microorgan- 

 isms and in the inoculation of substances into living cells," Philippine 

 J. Sci., B, 307-360, 1914. 



Berdan, Helen B., "A developmental study of three saphrophytic chytrids. 

 I. Cladochytriimi hyalimim, sp. nov.," Am. J. Botany, 28: ^22-A}8, 1941. 



