118 TBINIDAD AND TOBAGO BULLETIN. \XIX. 3. 



cuttings liad failed to grow while only two out of the 79 healthy cuttings 

 were dead. Further observations are needed to see if these results are 

 significant. 



Other Plants Infected. 



A number of Trinidad plants have at times mottled leaves closely 

 resembling the conditions produced by mosaic disease, but the sugar 

 cane mosaic has so far only been found on corn (maize) and one local 

 species of grass. 



In the early part of August, 1920 TMr. C. M. Roach brought in a 

 plant of corn-grass {Mauisurus exaltata) with the terminal leaves 

 affected in a manner exactly resembling mosaic disease. An attempt 

 was made to grow the plant but it failed to re-establish itself. 



On August 14 the same observer reported the occurrence of mosaic 

 disease on corn in same small farmers' plots in the St. Augustine district. 

 On September 8 I visited the locality and found, as reported, about 5' to 

 10 per cent, of the corn plants infected in a manner resembling mosaic 

 disease. 



The field in which the corn was planted was one from which cane 

 had been recently dug out owing to mosaic disease. It was suggested' 

 that the corn plants had become infected from being planted in the holes 

 from which the diseased cane stool had been removed (see below). 



The symptoms of the disease differed in several ways from the typical 

 su"ar-cane mosaic. The pale areas on the leaf were smaller, more 

 rectangular, and often crowded together in one part of the leaf while the 

 rest of the leaf appeared quite healthy. In a few cases the outer leaves 

 -were infected while the i)uier leaves appeared quite healthy. 



The field was visited again on October 8 and only a very few corn 

 plants were found to be infected, although none had been dug out. It 

 xippeared as if many plants had recovered and thrown off all signs of 

 the disease. 



In view of these conflicting observations the question of the identity 

 of the two diseases was left open, but a recent report by E. W. Brandes 

 on mosaic disease of corn in the United States {Jonrn. of AoricuUitrai 

 Bcsearch. XIX, 1920. .') 17-522) leaves little doubt on the subject. 

 Brandes describes in detail the symptoms which we observed, including 

 ihe frequent recovery of the plant, and has been able to prove, by 

 transferring the disease to cane by means of insects, the identity of the 

 two infections. 



Brandes further records the same disease on Guinea-corn {Sorghum) 

 Lut this crop is nut coriiUion in Trinidad and so far no mosaic disease 

 has been discovered on it. 



The presence of the mosaic disease on corn, although making the 

 extermination of the disease more difficult in the wet season, is not 

 very serious occurrence as there is no corn growing for at least three 

 months in the dry season, so there is no danger of it carrying on the 

 •<lisease from one season to the next. 



