890 



" 3. Tliat the disease may occur independent of Aphides. 



" 4. That Aphides may abound on a plant without producing the 

 real disease. 



" 5, Hiat the results produced by the attacks of Aphides upon a 

 plant are of a widely different character from those exhibited by the 

 plants attacked by this disease. 



" 6. That the disease in question may appear in the offspring of a 

 sound parent tuber ; and 



" 7. That the disease appears in many respects to be analogous to 

 the cholera, and may thence, for the sake of distinction, be termed the 

 potato cholera. 



" The facts already before the public fully confirm these arguments, 

 which are corroborated by other circumstances which I have noticed 

 within the last few days in my own kitchen-garden in Hammersmith, 

 and which are briefly as follows : — 



" On the 4th inst., a few plants were observed sickly in appearance, 

 with the leaves drooping and yellow in colour ; the remainder of the 

 crop having a remarkably healthy appearance and being singularly 

 free from insects of all kinds. 



" On taking up these drooping specimens, the haulm or stem for 

 about two inches below the surface of the ground was found to be 

 dried and shriveled up in appearance, and of a dirty brown colour ; 

 whilst the tuber from which it had sprung, and which had been set 

 entire last autumn, was still found perfectly sound, thus proving the 

 absence of disease inherited from the parent plant. With the exception 

 of these few plants the entire crop retained its healthy appearance 

 until Sunday afternoon, the 13th instant, when a great number of the 

 plants in two of the beds were observed flagging, just as though they 

 had been trampled over by dogs, which has since been followed by 

 the same appearance in other parts of the garden. It is proper here 

 to state that no attempts had been previously made to rid the plants 

 of insects, nor had the ground received other than the ordinary 

 treatment ; the last year's crop in my garden having been singularly 

 free from disease. On examining some of these plants on the 

 following morning, the haulm below the surface of the ground was 

 found to present the same dried, withered, and discoloured appearance 

 as in the specimens examined ten days previously ; the fibres of the 

 roots being likewise dry and incapable of performing their proper 

 functions, and which would produce discoloured blotches on the 

 leaves in a subsequent stage of the disease. The plants at the same 

 lime were free from insects, and the ]3arent tuber remained in several 



