On tlie Potato Disease. 
3G3 
trated. But whether or not these plants, or any others which I 
have fouiul and drawn, are the true botrytis infestans (figs. 1, 2, 
4, 5, a; and fig. 4, b), it is clear they must be very nearly allied, 
A. 
a be 
1. 2. 
On (leal slioots from disease.l potitoes from On rotten moist stalks, from market garden. 
Sydenham, jipril 11, 1845. Plants p?l- April 17. .\pril 7, tuft white, 
lucid, tufts n liite. 
On Mr. B.'s leaf, April 16, the 
large plant floating over the 
edge of the leaf, when 
cat, pellucid ; large clusters 
opaque if not in a good light ; 
tuft greviah. 
On mould in flower-pot, in which 
diseased potato was planted ; 
brilliant pellucid ; taf^ steely- 
white, some creamv afterwards. 
April 11. 
On potato-leaf damped 
and placed over mil- 
dew, on flower-pot. 
ADril 11. 
Drawn April 20. 
a, b, e, d, e, f, sporidia wliich have discharged their contents on these plants. 
Botrytis infestans. 
as well in their habits as in general characters ; for, having plucked 
a small leaf from one of my potatoes, and placed the under- side 
of it upon the mould in the flower-pot, in doing which the leaf, 
being damped, licked up a little fine earth from the surface, in' 
eleven days I found the same species growing on the decaying 
leaf as drawn in fig. 5, A. It will be perceived that the plants 
ihus obtained approach still nearer* in appearance to those ou 
Mr. Berkeley's leaf than those do which were found on the bare 
mould, although they sprang from the spores of the latter. I also 
scraped a small portion of the under-side of a living potato-leaf, 
and stuck a little of the mould upon the spot, and in a few days 
that part of the leaf was covered with plants of thj same species, 
but smaller than either those on the mould or those on the de- 
caying leaf. The fundus, however, did not spread heyond the spot 
Xh^X I had abraded. Two things are proved by these experi- 
ments; namely, that plants of fungi, so closely resembling the 
* Professor Henslow thinks it not improbable that uredo becomes puc- 
cinia ; and I am quite cert.iin these plants ^rew much larger and became 
more branched on moist decaying matter than on the livinsc leaf. 
VOL. VII. 2 c 
