LEAKE AND RAM PRA>SAjj. 51 



In Egypt Foaden* has drawn attention to the difficulty attach- 

 ing to the complete eradication of the inferior Hindi cotton by an} 

 method of roguing. Ballst has noted the mixed nature of the crop 

 and, from his observations, calculates| that ' ' all the kinds of cot- 

 ton which I have grown in Egypt are liable to at least five per cent, 

 of cross-fertilisation per annum. § 



Observations on the incidence and extent of Cross-feetiliza- 



ATION IN the held. 



This subject has been dealt with very briefly in an earHer note|| 

 in which a few early observations on the occurrence of natural cross- 

 fertilisation in Northern India were described. Two instances alone 

 were described in any detail and since these have formed the 

 subject of further experiment, they may be treated more fully 

 here. 



In the first case, a single plant of a number belonging to the 

 forms included under the term G. neglectum Tod., which were self- 

 fertilised, gave offspring whose several leaf factors ranged over the 

 entire scale while the offspring of the remainder were pure to this 

 character. Eleven of the offspring of this plant, having leaf factors 

 of different values, were again self-fertilised and in the subsequent 

 generation it was found that those plants having a factor 



2or yS bred pure, while the intermediate forms gave rise to a 



series of plants with leaf- factors of most divergent values. The 

 results are given in Table III, section {a). If this is compared 

 with section (6) of that table, which gives the results obtained 

 from a cross purposely effected between two types known to be 

 pure, the similarity will strongly suggest that the plant in question 

 was the result of a cross between a broad lobed, and a narrow lobed. 



* Year-book Kheil. Agr. Socy., I'JO.j. 

 t Year-book Khed. Agr. Socy., 1906. 



* Jour. Agr. Sci. II, IHOS, p. 358. 



§ For furtlier reference to this subject, see also Aliotta, Riv. Crit. del Genere Gossypiun 

 Unfortunately opportunity for consulting this work has hitherto been wanting. 

 II Jour, As. Socy. Bengal IV, 1908, p. 13, 



