JEHANGIE FARDUNJI DASTUR. 213 



a metal one, as the powder did not always get thoroughly wetted by 

 the water used. The liquid was then strained off through a fine wire 

 gauze strainer, and 10 grammes of agar melted in a small amount of 

 water were added to it, the medium was then made up to 500 c.c. 

 by the addition of the requisite amount of water. It was then boiled 

 to thoroughly mix its constituents, strained again through a fine 

 piece of cloth into test tubes and autoclaved. 



Oat juice agar (50 4- 10 f 500). — Growth at first was not as rapid 

 as on French-bean juice agar. But later on the aerial mycelial 

 growth was as good as in the latter. Both the aerial and submerged 

 mycelium resembled those in French-bean juice agar, but the budding 

 hyphse of the submerged mycelium were more prominent in this med- 

 ium, especially near about where oospores were formed. Sporangia 

 and " resting " conidia were freely formed. Oospores were not as 

 luxuriantly produced as in French-bean juice agar. Even in this 

 medium they were found only when it was inoculated with a culture 

 grown on another medium. Stab cultures produced a very poor 

 growth, both of the vegetative and reproductive organs. This 

 medium Clinton found to be successful for the formation of oospores 

 of Ph. infestans? 



Clinton gives a very elaborate method for preparing this medium 

 but our simplified method has given us a medium in which oospores 

 have been fairly richly formed. Fifty grammes of crushed oats 

 such as are fed to cattle on the farm were cooked with about 300 to 

 350 c.c. of distilled water for half an hour in the steam produced in a 

 Koch's sterilizer. The cooked material was then strained through a 

 wire gauze strainer ; to the liquid was added 10 grammes of agar dis- 

 solved in a sufficient quantity of distilled water to bring it up to the 

 required 500 c.c. The medium before being poured into test tubes 

 was boiled again for a short time in order to thoroughly mix the 

 ingredients. The test tubes were then autoclaved. 



Maize com meal agar (50 + 10 + 500). — This medium was prepa iv< I 

 by boiling the meal in water and mixing it with agar dissolved in a 



1 Clinton, LJ. P. foe cit., 1909-UHO, p. 700. 



