94 
DISEASES OF TLANTS CAUSED BY PERONOSPOR.®. 
plants provided with bulbs, rhizomes, or transplanted with a large 
quantity of earth. 
3°. Exposed to frost , the leaves attacked hy the parasite are the 
frst killed. This advantageous result is known to market gardeners. 
It is necessary, both in this and the preceding case, to remove 
the withered leaves. It is probable that any weakening cause 
produces the same effect ; the decay, through damp of plants 
prepared for sale, is thus explained. Hence the use of solutions of 
sulphate alcalines, or solutions saturated with nourishing principles 
is to be recommended ; these would for the time slightly weaken 
the plant. It is dangerous to open the frames ; wind, which propa- 
gates the spores, should be avoided. 
Any infected or suspected frames should be opened separately. 
The frames should not all be placed all in order, that a general 
infection may be avoided. 
4°. Every year the situation of the crops should he changed ; fresh 
earth should be always used. 
The soil only should be watered ; the leaves should never be 
wetted, to avoid the attachment and germination of spores. 
5°. When the plant is in the young state it should be carefully 
protected, so that it may have the start of the parasite, which, 
later on, is less to be feared, owing to the imbrication of the leaves. 
The evil will be much lessened by following these recommenda- 
tions. Independently of these precautions, is it possible to prevent 
the putrefaction of lettuce leaves attacked by Peronospora ? These 
leaves die through exhaustion ; to oppose this, one may endeavour — 
a. By keeping the plants gathered at a very low temperature 
until they are required, so that the parasite may be destroyed. 
b. By gathering the lettuces with their roots, so as to prevent 
the exhaustion of any leaves already infected. 
Practical men must judge which of these two methods is the 
best. Further details and explanations on this subject will be 
given in a more extended publication. 
SOME EXOTIC FUNGI. 
By M. C. Cooke. 
The following few species have been received from various corres- 
pondents, as indicated in each instance. 
Blelanogaster durissimus. Che. 
Subglobosus, compressus, difformis aut sulcatus, laevis, durissi- 
mus, atro luscus, demum nigrescens. Peridio crasso, subnitido ; 
carne mire lacunoso, ochraceo albo ; lacunis majusculis, creberrimis, 
atris. Sporis oblongo-ellipticis, inaequalibus, brunneis ‘005-'008 
X *003-*005 mm. Odore fortissimo. 
On the ground. Chakrata, North of Delhi, India. (Baden 
Powell, Esq.) 
They occur a few inches below the surface of the soil, only dur- 
ing the rainy season, at about 8,000 feet. They are occasionally 
