570 Scientific Proceedings, Royal Duhlin Society. 



In 1909' and 1910" Jones gave further particulars of his pure cultures of the 

 fungus which he had grown continuously for four years. Oogonia-like bodies 

 were found in cultures on raw potato-, in potato gelatine and on Lima hean 

 agar. In some cases apparently fully developed resting-spores were discovered 

 in his cultures, but no traces of real antheridia were found. The spores are 

 described as having a thick spiny brown outer wall with densely granular 

 contents. They resembled in a general way the oospores of otlier Perono- 

 sporaceae, and bodies similar to them were also seen in potato foliage which 

 had been destroyed by the blight fungus.' 



The first announcement of the production in pure cultures of undoubted 

 oospores was made by Clinton* in 1911, in an article in which the previous 

 literature on the subject is summarized, while full details of tlie media used 

 and of the results obtained were published later in the same year.'* Out of 

 about seventy-five media experimented with three are mentioned as having 

 given specially good results, viz., Lima bean-juice agar, a "combination 

 medium" made up from Lima beans, oats, peanuts, potato, sweet 

 corn, wheat, and agar, and lastly oat-juice agar, which is stated to have 

 stood alone so far as the production of oospores is concerned. On it antheridia, 

 oogonia, and oospores were developed ; and in the paper quoted these are fully 

 illustrated and described. 



It will, we think, at once be conceded that corroboration by other workers 

 of such interesting and important results was highly desirable, and, seeing 

 that we enjoyed particular facilities for work on P. infesians owing to the 

 establishment by the Department of Agriculture and Technical Instruction for 

 Ireland of a temporary station in the west of Ireland (where the potato blight 

 is particularly prevalent) for special investigations into the various diseases to 

 which the potato is subject, we commenced early in the summer of 1911 the 

 study of the development of this fungus in pure cultures. 



Over twenty media or modifications of media have been experimented 

 with, and many hundreds of cultures have been studied during an uninterrupted 

 period of some eighteen months. True oogonia, antheridia, and undoubted 



iJones,L.R. — " Resting- Spores of the Potato Fungus P/ti/<o2)A<Aora infestans." Science, N.S., 

 vol. XXX, 1909, p. 813. 



2 Jones, L. R., and A. B. Lutman. — " Further studies of Pliytophthora infestans." Science, N.S., 

 vol. xxxi, 1910, p. 752. 



3 Since the above was written we have received a fuUer description of Jones's work contained in a 

 paper entitled, " Investigations of the Potato Fungus Phytophthora infestans," by L. R. Jones, 

 N. J. Giddings, and B. F. Lutman, and published in 1912 by the Bureau of Plant Industry, U.S. 

 Department of Agriculture, Washington. 



* Clinton, G. P.—" Oospores of Potato Blight." Science, N. S., vol. xxxiii, 1911, p. 744. 

 = Clinton, G. P. — " Oospores of Potato Blight, Phytophthora infestans." Rep. Conn. Agiic. Exp. 

 Sta. for 1909-1910. 1911, p. 753. 



