DESCRIPTIVE CATALOGUE. 



175 



1866, in which the author recognized 7 species, with 8 others in doubt. The other 

 monograph was by Agostino Todaro, published in 1877, in which are described 52 

 species, with 2 as uncertain. Hamilton sought to avoid confusion by dividing the 

 genus into 3 species, the white seeded, black seeded, and yellow linted, to which 

 he gave the names album, nigrum, and croceum. A recent publication, Index Kew- 

 ensis, recognizes 42 species, of which but a very few are of economic importance, 

 and mentions 88 others that have been reduced to synonyms, most of them being 

 synonyms of species in common cultivation. The great variability and the tendency 

 to hybridize makeit difficult to determine to which species a given plant may belong. 

 No cultivated plant responds so quickly to ameliorated conditions of soil, climate, 

 and cultivation as the cotton plant, and to this fact is due much of the confusion as 



Fig. 59.— Sea Island cotton. 



to species and varieties. Another factor entering into the confusion is the imper- 

 fectly known types that have been described as species. It has been stated that 

 some of the species now widely cultivated are wholly unknown in a wild state, and 

 some of the specimens described by Linnreus were in all probability from plants 

 that had long been in cultivation. The work of establishing the origin of the cul- 

 tivated species has been still further complicated by the exchange of seed from coun- 

 try to country that has been going on for at least four centuries. 



Among the species recognized to be of more or less economic importance are G-. 

 arboreum, G-. neglectum, G-. brasiliense, G. herbaeeum, G.barbaclense, and perhaps a few 

 others. In this country only the herbaceous cottons are cultivated to any extent. 

 The shrubby and arboreous are grown occasionally as curiosities, but they seldom 



