106 
either to restore the natural checks which man has abolished, or, 
as this can from the circumstances of m case ied be 
to substitute artificial ones in their place. Anda 
practice, by an attentive study of the habits of the parasite this 
can generally be effected s ihe i injury it inflicts circumvented. 
The difficulties which beset tea-culture in Assam are o xe 
illustration of these general Tic iples. But the Government of 
India does not possess any trained mycologist in its service, and 
no one was available for the study of the * Blights’ Bises affect 
Indian tea-culture, but Dr. Watt, its Reporter on Economic Pro- 
ducts. When a similar investigation was needed for the DGUDS 
crop, it was entrusted to a gardening member of the staff of the 
Royal Botanic Garden, Calcutta. Dr. Watt was obliged to have 
recourse to Kew for the technical investigation of the most serious 
maladies with which the npg dde € to contend. The 
Del ang report has been drawn up, from material transmitted » 
Dr. Watt, by Mr. Massee, a Prisbfpel Prud in the Herbarium 
of the Royal Gardens. 
GREY BLIGHT. 
(Pestalozzia Guepini, Desmaz.) 
The amount of injury caused to the tea tagene by this 
fungus is estimated by “es Watt as follow “T regard the 
Grey Blight as very alarming, a disease that "t — checked may 
easily reduce the productiveness of gardens by fifty per cent, lt 
mad 
examination of the fungus sent from Assam on leaves of 
the tea plant, showed it to be identical with the parasite common 
on leaves of cultivated species Camellia in Europe. The 
fungus first appears under the form of small grey spots, more or 
infrequently run into each other, forming large, irregular blotches 
which often eventuais cover the greater portion of the surface of 
the leaf. During increase in size, the spots are often bordered by 
a narrow dark line. The grey or sometimes white colour of the 
spots is equally évident on both éco of the leaf, and is due to 
the disappearance of the chlorophyll, and the subsequent death of 
the cells composing € tissue of the leaf. The mycelium of the 
of the fungus becomes aggregated in numerous dense tufts just 
beneath the cuticle, more especially on the upper surface of the 
leaf. On the tips of these aggregations of slender, erect hyphae, 
or conidiophores, which spring from a basal pseudoparenchymatous 
stroma, the conidia are borne, As these clusters of conidia increa 
