On a Disease of Tradescantia. 
BY 
ALBERT HOWARD, BA., 
Scholar of St. John's College, Cambridge. 
With Plates IV and V. 
D URING the summer of 1899 it was found that two 
species of Tradescantia , viz. T. fluminensis (Veil.) and 
T. zebrina (Hort.), growing in the greenhouses of the 
University Botanical Gardens, were suffering from an epidemic 
disease which showed all the symptoms of attack by a Fungus. 
In some of the houses the host-plants were completely killed 
off over considerable areas, while in others the plants, 
although obviously infected, nevertheless continued their 
growth in a more or less normal manner. It was noticed 
that many of the dead leaves and stems, in addition to 
showing dark spots and patches, were covered with long 
white conidiophores of a Botryosporiam (Fig. 10), and also 
that dead leaves which did not show these structures 
speedily became covered with them when placed on damp 
blotting-paper under a bell jar. It appeared possible that 
this Fungus was the cause of the disease, and it thus became 
necessary to obtain pure cultures to follow out the complete 
LAnnals of Botany, Vol. XIV. No. LIII. March, 1900.] 
