8 



lint to decay or rot, and ultimately spreads so as to involve 

 all the seed and lint within the boll, and may then even 

 affect portions of the carpels. Figure 2 shows a diseased 

 boll cut open, the seed and lint being affected. If the boll 

 becomes diseased early in its growth, say four weeks before 

 it is ripe, the disease will cause the entire boll to rot before 

 the carpels can open at all. If, however, the disease ap- 

 pears later, when the boll is full size or nearly so, and the 

 seed and lint nearly developed, the carpels may open or separ- 

 ate slightly at the tips, and thus admit the small sap-beetles 

 that will enter and feed upon and breed . in the decaying 

 contents of the boll, and thus help to diseutegrate it. 

 Saprophytic and other fungi finding here a suitable pabu- 

 lum may now appear and infest the decaying boll. Of course 

 these diseased bolls can never mature lint or seed. 



Should the disease appear still later when the boll has 

 partially ojjened, or is nearly ready to open, the rot may 

 affect only a few seed and a small portion of the lint before 

 the boll opens and dries. In this case the boll would ap- 

 pear nearly normal and a large portion of the lint and seed 

 would be perfect, especially that exposed to view, while that 

 nearest the petiole would be affected. This is really the 

 most serious condition so far as the cotton growers at large 

 are concerned, since it is probably here that the great dan- 

 ger of spreading the disease to unaffected areas is to be 

 found. In the other cases the contents of the boll is either 

 wholly or more or less destroyed, and the boll fails to mature 

 or develop lint ; and if it opens it is but slight, and the boll 

 is known to be diseased or imperfect and is never picked. 

 But when the disease is so slight as to allow picking, the 

 effected seed and lint is mixed unconsciously and taken to 

 the gin, where the seed becomes mixed with seed from un- 

 affected district ; and thus all the seed that passes through 

 the gin is liable to be infested with the germs of the rot 

 disease, and finally to become distributed to distant parts of 

 the country. Too great a precaution in regard to this method 

 of spreading the disease can not be taken. The cause of 

 the disease has been shown to be a micro-organism (bacteria) 

 of extreme minuteness, and one that is found in innum- 



