282 DISEASES OF CROP-PLANTS 



sporadic, much more so than with curly-leaf. A few cases have 

 been seen in which its incidence was fairly general over the whole 

 or part of a field, but more often the majority of the plants have 

 been normal. 



Sometimes a single abnormal plant, sometimes two or three, 

 have occurred in a large field. 



History and Distribution. 



Attention seems to have been first attracted to the logger- 

 head affection in 1910, in which year it appeared to an alarming 

 extent on an estate situated towards the western extremity of 

 the island of St. Kitts. Then, as later, it was not regular or 

 universal in an}- field. The seed was from the local Experiment 

 Station at La Guerite. It has since been noticed to some extent 

 in the same district every year. In 1913 it was severe on two 

 estates 2 or 3 miles to the north-west. Again the cotton happened 

 to be from local seed, and in consequence a change was made in 

 1914, and seed of a Barbados strain, grown three years in St. 

 Kitts, was used. Early plantings from this seed were so badly 

 affected that a fairly large area was cleared about June and 

 replanted. 



In the neighbourhood of Basseterre, sporadic examples have 

 occurred each year since the affection was recognised, and have 

 been usually rogued out. In July, 1914, the affection appeared 

 to a much greater extent, but still with a scattered distribution, 

 in various fields situated on the La Guerite lands. This cotton 

 was planted, owing to the occurrence of early rains, some two 

 months earlier than is customary. 



In Nevis, though curly-leaf has been common on some areas 

 since 1911, the loggerhead affection has only occurred sporadi- 

 cally, and has not been regarded as of serious importance. In 

 1914 it was somewhat more common, and in two or three places 

 seriously affected small areas. One of these was a plot at the 

 Experiment Station planted with St. Vincent seed. 



Loggerhead has not been recorded from any other island. 



Conditions of Occurrence. 



As in the case of curly-leaf there is nothing to indicate a 

 parasitic origin for the loggerhead disease, or its transmission 

 by infection or by seed. The evidence as to the conditions 

 inducing its appearance is less definite than that regarding 

 curly-leaf. A plant recovering from the affection can occur 

 within a few yards of one of the same age just developing it. 

 Whole plots of similar age separated only by a road have shown 

 the same contrast. Frequently two plants, one healthy and one 

 badly deformed, have been seen growing in close contact from 

 the same " hole." 



The one definite piece of evidence bearing on the origin 



