820 MR. H. MARSHALL WARD ON THE 
the leaves being already wetted by a drizzling rain ; one leaf was 
then marked on each plant, and spores carefully placed on each 
in drops of water on the under surface. 
On one leaf of plant C a sowing was made, under the siphon 
&c. as usual; D remained untouched. : 
E and F remained untouched, as also did G. One leaf of H 
was infected under a siphon as usual. All this took place on 
December 23rd. 
On January 3rd, 1882, several leaves from both the exposed 
plants (A and B) had been torn off by wind &c. On several of 
the younger leaves were distinct, though small disease-spots ; 
these were partieularly noticed on the marked areas. During 
the following week the spots increased in number and vigour, 
and there could be no reasonable doubt that the plants had been 
infected as described earlier, and that 11 days (December 23 to 
January 3) had been occupied in the process. 
On January 4th a “ disease-spot” appeared on the leaf of 
the plant C, where spores had been sown 12 days previously; 
no trace existed on D, however, either then or later. 
The plants E; F, and G remained without a trace of disease up 
to January 12th, and no reason existed for supposing that any 
mycelium or “ disease? was imminent. 
The plant H, at the spot where spores had been sown 18 days 
before, developed a “ disease-spot ” on January 6th, on which 
spores appeared on January 10th. 
Now this experiment, the latest which I performed in Ceylon, 
appears in some respects the most instructive and conclusive 
which has yet been offered. 
It seems clearly to prove, Ist, that the nature of the soil, 
coffee-plant, and past circumstances &c. have nothing to do with 
the possibility of infection ; 2nd, that previous experiments had 
conclusively established the normal course of the “ disease ;” and 
3rd, that, provided the plants are kept sheltered from the fungus- 
spores, there is no fear of their incurring the inroads of the pest. 
For additional evidence on these points the reader is referred 
to my previous Reports. 
With regard to the exposed plants A and B, it may be asked, 
How was the moisture necessary for germination supplied, since 
no siphon was used? The answer is given by my diary of the 
weather. The week before was cloudy and showery, and the spores 
employed were already prepared for rapid germination. Then :— 
