LKAKE AND RAM PRASAD 125 



vellow. Boll large. This group includes a series of types received 

 from China, of which the following have been employed : — 



Corolla, yellow oycnl : seed with fuzz . . Type 12. 



,, .. .. .. naked . . Type 13. 



,, ,, without eye : seed naked .. Type 14. 



(2) Plant differing from Type 2 maiidy in tlie character of 

 the secondary branches. The group includes a complex series of 

 forms from Persia which has been dealt with by us elsewhere (21). 

 The simplest form is the true G. herhaceum of Todaro. 



(3) Gossijpiunt hirsuUim. Linn. — This plant, which yields the 

 bulk of the American cotton crop, has formed the basis of numerous 

 experiments both in the United Provinces and in other cotton tracts 

 of India and is to be found locally throughout the formei-. Selected 

 plants from cultures dciivcd fjoni vai'ious souices have been 

 used. 



(4) Goss/jpii/m Stochsii, Max. Mast. A wild form of Gossy- 

 piwn found on the limostoiio hills ai'ounfl Karachi from whence 

 seed was obtained. 



PoUination. 



The cotton flower is hermaphrodite (Plate Xlll). The stigma 

 becomes receptive and the stamens liberate their pollen shortlv 

 after the flower opens. These organs are so distributed that self- 

 ])ollination follows almost immediately. Associated with this 

 arrangement of organs we find that in almost every case self-ferti- 

 lization is effective. A detailed discussion has been given on a 

 former occasion (20). 



When, however, the (piestion of effecting cross-fertilization is 

 considered, the genus Gossf/pium, at least as far as the cultivated 

 forms are concerned (for of wild species G. Stocksii, M. Mast, alone 

 has been studied), appears to fall into two maiked groups, the 

 members of each of which are fertile infer se, but exhibit complete 

 sterihty when attempts are made to effect a cross between the two 

 groups. These two groups have already been referred to above as 

 characteristic of the Old and the New World and as respectively 

 characterised by united and free bracts. 



