COTTON FIBRE 43 



3. Similarly the character of easily separable floss would not Separable 

 seem to be an acquired one in cultivation ; in other words, it is not floss ' 

 necessarily a consequence of man's selection. It is a condition that 

 prevails naturally, with certain undoubted wild species, but which 



very possibly has been taken advantage of in industrial selection 

 and thus intensified by man. The firmly adherent flosses could 

 only be removed by being plucked off by hand or by means of 

 specially constructed gins ' saw-gins.' The end of the staple has 

 thus to be torn from the seed cuticle. All such staples are accordingly 

 ruptured, and, seen under the microscope, have their lower thicker 

 ends irregularly burst open. The easily separable flosses, on the 

 other hand, often seem to part from the seed naturally, to fall 

 away from the cuticle like ordinary caducous hairs, the result being 

 that under the microscope mature cotton fibrils of this kind manifest 

 little or no evidence of the rough treatment characteristic of the 

 other staples. (Of. with p. 246.) 



This is an industrial distinction of no small importance. 



4. Of the four groups above indicated perhaps (c) those with a Fuzz but 

 fuzz not referable to two layers (an outer and an under coat) are of 



least value to the cotton-grower. None of the members of that 

 group seem ever to have been cultivated, or to have in any way 

 contributed to the cultivated stocks of the world. They are, how- 

 ever, the most widely spread assemblage ; for example, G. Sturtii 

 is found in Australia. G. Davidsonii and G. Harknessii in California, 

 G. Darwinii in the Galapagos Islands, G. tomentosum in the 

 Hawaiian Islands, and G. Stocksii in India and Arabia. And it 

 may be added that structurally they are the least cotton-like members 

 of the genus Gossypium, their free and often clawed bracteoles 

 bringing them very near to Fugosia and Thespesia. Were a selection 

 of the wild species to be drawn up with a view to some of them 

 being used as possible future stocks of improved cotton staples, the 

 existence of the series of fuzz- but not floss-yielding forms might 

 safely be ignored. And this statement sweeps away, I trust, satis- 

 factorily and accurately the misconception, entertained by some 

 writers, that G. Stocksii may be the ancestral form of G. obtusifolium, 

 if not of G. herbaceum. 



5. The exclusion of the non-floss-yielding species practically Floss but 

 leaves two groups that have to be considered, since (a) and (b) can be na t e d 

 united into one, viz. those that possess both a fuzz and floss and seeds, 

 those that have a floss only. But let it be here added that, of the 



