DISEASES OF COTTON 281 



growth, locally named loggerhead, occurred to about the same 

 extent. This appears to be closely similar in nature, but produces 

 changes in the form of the plant which are in many respects the 

 exact reverse of those seen in curly-leaf. 



The most striking feature of the loggerhead form of growth is 

 the shortening, to a greater or lesser degree, of the internodes of 

 both stems and branches. A plant which is affected at an early 

 stage of growth assumes the form of a low dense bush, with the 

 primary leaves, and the shortened reproductive branches with 

 their leaves and flowers, all crowded together on the shortened 

 vegetative axes. If the plant becomes affected only after normal 

 growth has been made, then the tops of the main stem and of the 

 vegetative branches show similar close bunchy masses. The 

 flowering branches have numerous internodes, so that large 

 numbers of flower buds are produced. 



The leaves of the loggerhead form are very distinctive. They 

 are normal in thickness ; the general colour is a dark green, 

 usually distinctly darker than that of the leaves of normal 

 plants ; there is no tendency to the crimping at the edges which 

 is the most conspicuous feature of the other form, but fre- 

 quently the leaf substance is puckered along the main veins 

 owing to their insufficient elongation ; the secondary veins, 

 instead of diverging at the usual wide angle may be tied at a 

 narrow angle to the primary veins for some distance, apparently 

 from the failure of the intervening ground tissue to expand. 

 Such undeveloped spots are almost transparent and of a light 

 yellow colour. In many cases there is not this interference 

 with the form of the leaf, but in all cases there is a definite 

 mottled effect produced by the presence of lighter green or 

 yellowish areas. In all typical cases the mottling is quite difl'erent 

 in appearance from the diffused yellowish discoloration along the 

 course of the veins which has been already described as occurring 

 in some cases of curly-leaf. A few examples have been noticed, 

 however, where in plants of the loggerhead form the light areas 

 have followed the course of the veins. In such cases the yellow 

 colour has usually been more definite than in the curly-leaf 

 examples, but occasionally the approach is very close. This 

 was seen in plants in which the suppression of the internodes was 

 hardly noticeable. 



As in the case of curly-leaf, large numbers of flower buds 

 turn black and drop in their earliest stages. This symptom 

 cannot, however, be regarded as a specific character of these 

 affections, since the same thing has been observed on cotton 

 plants of normal form when exposed to unfavourable conditions. 

 The abnormal condition of the flowers described in connection 

 with curly-leaf also occurs in plants of the loggerhead form. 



The loggerhead form of growth can be assumed at any stage 

 at which active growth is proceeding, including plants only a 

 few inches high. Most commonly its occurrence is distinctly 



