Cultivated-Plant Study 



669 



which cover the bud and remain attached to the ripened boll. The 

 calyx, looking like a little saucer, also remains at the base of the boll. 

 The boll soon assumes an elongated, oval shape, with long, pointed tip; 

 it is green outside and covered with little pits, as large as pin points. 

 There are, extending back from the pointed tip, three to five creases or 

 sutures, which show where the bell will open. If we open a nearly 

 ripened boll, we find that half way between each two sutures where the 

 boll will open, there is a partition extending into the boll dividing it into 

 compartments. These are really carpels, as in the core of an apple, and 

 their leaf origin may be plainly seen in the venation. The seeds are 

 fastened by their pointed ends along each side of the central edge of the 

 partition, from which they break away very easily. The number of seeds 

 varies, usually two or three along each side ; the young seeds are wrapped 

 in the young cotton, which is a string^-, soft white mass. The cotton 

 fibres are attached to the covering of the seed around the blunt end, and 



1, The cotton flower cut in half, showing the stamen-tube at the center, 



up through which extends the style of the pistil. Note the bracts 

 and calyx. 



2, A young boll, with calyx at its base and set in the involucral bracts. 



usually the pointed end is bare. When the boll opens, the cotton becomes 

 very fluffy and if not picked will blow away; for this cotton fibre is a 

 device of the wild cotton for disseminating its seeds by sending them off 

 on the wings of the wind. Heavy winds at the cotton-picking time, are a 

 menace to the crop and often occasion serious loss. 



The mechanism of the opening of the cotton-boll is very interesting; 

 along the central edge of each partition and extending up like beaks into 

 the point of the boll, is a stiff ridge, about the basal portion of which the 

 seeds are attached; as the boll becomes dry, this ridged margin becomes 

 as stiff as wire and warps outward; at the same time, the outside of the 

 boll is shriveling. This action tears the boll apart along the sutures and 

 exposes the seeds with their fluffy balloons to the action of the wind . The 

 ripe, open, empty boll is worth looking at; the sections are wide apart 

 and each white, delicate, parchment-like partition, or carpel, has its wire 

 edge curved back gracefully. The outside of the boll is brown and 

 shriveled, but inside it is still white and shows that it had a soft lining for 

 its "seed babies." 



The amount of the cotton crop per acre varies with the soil and 

 climate; the amount that can be picked per day also depends upon the 



