HARDWICKE'S SCIENCE-GOS SIP. 



99 



THE POTATO DISEASE. 



WHAT with the difficulty still remaining as to 

 the curability of the inicro-fungi attack 

 commonly called the Potato Disease, and the 

 threatened invasion of the Colorado Beetle, our 



botanist, Mr. Worthington G. Smith, F.L.S., once 

 more ventilating the question in the last number of 

 the Popular Science Review, in an article headed 

 " Side Lights on the Potato Disease," from which 

 we have borrowed the illustrative woodcut. Mr. 

 Smith thinks that an undue importance has been 



Fig. 68. Potato-disease fungus {Peronnspora infestans) in situ, x 225 diam. {Camera lucida). A, B, thickness of 

 lamina of leaf ; C, C, Stomata, or breathing-pores ; D, D, Hairs on leaf; E, E, Threads of Peronospora infestans ; 

 F, F, Spores; G, G, Privileged spores, containing ciliated zoospores ; which are seen free at H, H. 



much-prized tuber seems to be in no small danger 

 of extinction. Any information respecting the 

 former is of value to the scientific agriculturist, 

 and we are therefore pleased to see a well-known 



given to the non-discovery of oospores in the potato 

 fungus (Peronospora infestans). Little is known, at 

 present, of the winter life of this pest, and the 

 writer thinks that the earth from which diseased 



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