FUNGUS DISEASES 87 



fairly large bacterial cavities are formed. If transverse 

 sections of leaf or stem are let stand for a short time, the 

 cut surfaces soon become covered with bacterial drops 

 which have been forced out from the ends of the bundles, 

 If the sections, when freshly cut, are put in large covered 

 dishes away from the air, pure cultures of the organism 

 may be obtained directly from these drops. If the disease 

 is not severe, or a plant does not become infected until it 

 has just formed a bunch of fruit, it may remain perfectly 

 healthy-looking, but many of the young fruits, or ' fingers, ' 

 do not properly mature : they remain small and eventually 

 become black and rotten. In such cases it is found that 

 there are some discoloured bundles filled with bacteria in 

 the leaves, stem, fruit-stalk, or fruits. When diseased 

 suckers are planted, the terminal leaf frequently turns 

 black and dries up, so that the plant dies." 



Rorer states that the true Panama disease also exists in 

 Trinidad. 



Surinam. In April 1911 Essed published in the Annals 

 of Botany* an account of a so-called Panama disease 

 which is virulent in Surinam, and described a fungus 

 which he believes is the cause of the disease. The disease 

 appeared on fields only one year old, and the loss amounted 

 to 25 to 75 per cent, of the second and third crops. On 

 some fields the entire crop was lost. It is only since exten- 

 sive fields of the commercial banana (Jamaican banana, 

 Gros Michel) have been planted that this disease has 

 attracted attention. This banana appears to be most 

 susceptible ; the " Lady's Finger " banana, the common 

 plantain, and the China banana are not subject to it. 



The first symptoms of the disease in Surinam, according 

 to Essed, are a withering of the margin of the leaves and a 

 discoloration along the midrib ; sometimes the youngest 

 (unopened) leaf withers, the others remaining healthy ; 

 sometimes the older leaves wither before there is any 

 arrest of growth in the youngest leaf. Then development 

 ceases, the leaves droop, the plant looks water-starved, 



* xxv. 343. 



