Vol. ON No. 1.] Haperimental Breeding of Indian Cottons. 15 
NS] 
of numerous measurements—numbering, in all, over 10,000—it has 
been found that the value of the factor wo 

(vide diagram opposite) 
gives the readiest means of estimating this character. Full dis- 
cussion of this factor, its legitimate use and its limitations, fall 
beyond the scope of the present note. The plants for which this 
factor has been determined, number considerably over one thousand, 
and the limiting values have been found to be 0'8 and 5:1. __Plants 
be classified as bearing palmatisect—or ‘narrow ’-lobed!—leaves. 
This numerical expression for the ‘ breadth’ of the leaf lobes will 
be, in future, referred to as the leaf-factor of the plant. 
If, now, a plant of which the leaf-factor is less than 2°1, be 
crossed with a plant of which the leaf-factor is greater than 3 0, it 
is found that the leaf-factor of the offspring in the F, generation 
aproximates remarkably to the arithmetic mean of the two 
parental leaf-factors. This appears to be true for all crosses 
whether they are made between oe extreme ag of G, neglectum 
or ae such eal types as G. arboreum (leaf ‘ narrow ’- 
lobed) and G. herbaceuwm (leaf me broad ‘ lobed). The following 
examples illustrate this, the leaf-factors of the parent being 
taken as the average of the values found for the offspring, :— 

Lied faltinn ‘No. of plants used 
* |in determination. 




seed parent G, indicum *# a 1°64 | 20 
pollen parent G. arboreum _... 3°21 | 3 
mean of factor of parents... 2°42 | i 
G. indicum x G. arboreum at 2°45 10 
No. of plants used 

carapace in determination. 
seed parent G. indicum “ 1-64 ae ie 20 
pollen parent G. neglectum  ... 3°35 | 20 
mean of factor of parent ee 2°49 | - 
G. indicum x G. neglectum _... 2°42 | 17 


1A tpi 1 corimonly sini. There is no a proirt reason for c 
sidering the two expressions—the de sca ~ which the leaf is divided and iis 
‘breadth ’ of etn leaf lobes—as synonymous, The leaf-factor, however, in- 
volves both characters ; and since this dena to behave as a definite character, 
there is reason to believe that they may be considered to be so. 
this note distinction between G, indicum and 
G. neglectum is unnecessary. 
