PEDIGREE 11 



more recondite peculiarities. It is to this phenomenon, 

 super added to a very few constitutional changes in length, 

 that the whole range of length in different kinds of cotton 

 is is due. 



To the ordinary Fluctuation (PL V.), which acts on 

 the constitutional basis just described, producing 



differences between the crops in different 

 Fluctuation. " ., . ,.,_. 



parts of the same country and in different 



years, we shall advert when discussing the development 

 of the fibre in the principal portion of this book. 



COMMEECIAL VAKIETIES. 



The subdivision of the three great divisions of the 

 genus Gossypium into those ultimate units in which the 

 crop is classified on Cotton Exchanges may be carried 

 to very fine distinctions of breed, or it may be very 

 rough, according to the social conditions of the country 

 of growth. 



As a rule, even in the least fine cottons, the trade name 

 covers a population of plants which are fairly closely 

 related, forming a "subspecies" of the genus, though a 

 different name may be given in the trade to the produce 

 of the same subspecies when grown in another district. 

 In any serious cultivation, however, and especially in 

 the finer cottons, the subspecies is cut up into named 

 varieties, which have usually originated in the chance 

 discovery of some well-favoured plant, and the multipli- 

 cation of its descendant. 



The discovery of such especially good plants implies 

 that the subspecies itself is not homogeneous, since we 



