FUNGUS DISEASES 93 



Microscopic examination of the sections of the root- 

 stock and the leaf -sheath revealed the presence of hyaline 

 or slightly coloured septate hyphae in or about the fibro- 

 vascular bundles. In some cases minute colourless, more 

 or less oval-shaped spores of a fungus known as Cephalo- 

 sporium have been noticed appearing in balls or clusters 

 from short stalks or conidiophores within the vessels. In 

 the course of a day the mycelium produced a new form of 

 crescent -shaped spores of the fungus known as Fusarium, 

 but no higher form of fructification than these two have 

 been noticed. 



Jamaica. A disease of the leaves in Jamaica was 

 reported by F. S. Earle in 1903.* The disease causes the 

 browning of the vascular bundles in the veins and midrib 

 of the leaf, followed by the blackening and eventual decay 

 of the whole leaf and its stalk. The disease does not extend 

 into other parts of the plant, but as new leaves open out 

 they also become affected. The diseased plants are stunted 

 and do not bear fruit. The disease appears to travel 

 slowly, and to have been introduced into the small field 

 by suckers from neglected patches in the neighbourhood ; 

 it did not spread later from the spot where it was first 

 noticed into the district round. Earle obtained cultures 

 of a bacterium from the diseased leaves which he sent to 

 Erwin F. Smith, of the U.S.A. Department of Agriculture, 

 Washington, who stated that he inoculated leaves of 

 bananas in Washington with this material, but without 

 result. 



The mycelium *j* of Marasmius semiustus Berk, and Curt, 

 penetrates the tissues of the trunk, and attacks the 

 embryonic flowers and flower -stalk, as they grow up 

 through the centre of the trunk. The fructifications 

 (small toadstools) appear on the surface of the trunk ; the 

 colour is white, becoming a yellowish brown as they dry ; 

 the pileus is to 1 in. broad, attached to its stem eccentric- 

 ally, at first convex, then flat ; gills wide apart and as they 



* Journ. New York Bot. Gard., iv. 



t Journ. Linn. Soc. x. 1869 ; W. Ind. Bull, x. 244. 



