Trade 

 require- 

 ments. 



Selection 

 of stock. 



Parts of 

 the cell. 



WILD AND CULTIVATED COTTONS 

 SO 



indefinitely. Enough has, however, been said to show that the 



microscopic study of the floss, in structural and physical properties, 

 gives one of the most certain of all keys to the improvement of the 

 staple. The influences of soil, climate, season, &c., on the growth of 

 the cells, their periods of maturity, extent and nature of cellulose 

 deposits, strength of the cells formed, their colour and silkiness, 

 degree of twisting, &c., are all vital aspects that must be closely 

 watched in relation to the requirements of the market for which 

 produced. 



There can be no doubt that the trade does not wish one and the 

 same staple from all the cotton tracts of the world. There are 

 merits, apart from length, in almost every known cotton, that it 

 becomes imperative to ascertain and develop. The influences of 

 soil, climate, season, and methods of production upon the desired 

 properties of the staple become, let it be repeated, the foremost 

 considerations of the scientific cultivator. 



No progress can be made where selection of stock on these lines 

 is neglected; it is co-equal with selection of species or race grown. 



But there are still a few other aspects of the microscopic study of 

 cotton that are suggestive of practical results. Eecapitulating some 

 of the peculiarities already made out, in order to secure continuity, 

 the cells may be said to close lengthwise as a first stage in their 

 ripening and drying. The approximately parallel bands of thicker 

 deposits thus come to appear as rounded margins to the resulting 

 ribbons. Owing to these deposits being laid down irregularly, how- 

 ever, and leaving as already explained, thinner portions exposed to 

 the drying influences, the ribbons rapidly get twisted on themselves. 



Parts of the Cell. Cotton hairs or fibrils may now be stained by 

 the ordinary tinctorial methods in the laboratory, in order to bring 

 out their structural peculiarities more clearly. Moreover, they will 

 have to be examined both lengthwise and in transverse section. 

 With such preparations carefully made it will be apparent that 

 cotton cells (hairs) consist of the following parts : 



(a) The cell-wall or cuticular envelope of the elongated hair ; 

 (6) The deposits of cellulose laid down within and upon the envelope; 

 and (c) The core of cell-contents filling up the central cavity. 



Irregularity in Growth. Presumably a bundle of cotton hairs, 

 from a specially selected seed, may have been employed in making 

 the preparations. If so it will readily be perceived that the three 

 parts just mentioned are not in all cases equally developed ; that is 



