FUNGUS DISEASES 89 



where they form sclerotia which give rise to little 

 spores. 



In the leaf -blade the fertile hyphse develop in or among 

 the palisade parenchyma cells ; some of them reach the 

 inner walls of the outermost parenchyma layer, forming 

 sclerotia, which, after remaining dormant for a time, pro- 

 duce spores ; the spores may remain in the sclerotium, or 

 the pressure of the surrounding tissues may force them 

 into the cells above ; they become free after the leaf has 

 decayed. The hyphse may also penetrate into the sub- 

 epidermal layers, filling the cells with sclerotia ; or they 

 may emerge on the surface of the leaf as little brown gall- 

 like swellings (Mycocecidia) ; sometimes they go back 

 through the epidermis or through the stomata, or they 

 ramify all over the surface of the leaf, producing numerous 

 sickle-shaped conidia. 



Essed found bacteria, but proved by inoculation of 

 healthy plants that the fungus, and not the bacteria, was 

 the cause of the disease as it occurs in Surinam. He was 

 not successful in finding remedies to prevent the spreading 

 of the disease. Plants once diseased, of course, cannot be 

 cured, and therefore remedies must be limited to a preven- 

 tion of spreading. Spraying with Bordeaux Mixture the 

 plants all round an infected spot and burning infected 

 plants is the natural suggestion to make as a beginning. 



The United Fruit Company employ an expert agent to 

 travel and collect every kind of disease-resistant commercial 

 banana for their plantations in Jamaica and in continental 

 America. They had great hopes at first of a variety which 

 was called the " Congo " banana, and was reputed to have 

 come originally from the West Coast of Africa. Although 

 immune from disease, and planted to some extent as an 

 experiment in Surinam in substitution of the Jamaican, 

 the fruit has not found favour with the fruit merchants, as 

 the fingers ripen irregularly and are apt to get broken at 

 the neck and drop off before becoming fully ripe. (See 

 under Surinam in Chapter XXIX.) 



Surinam Elephantiasis Disease. Besides the " Panama 



