42 hiheritaiice and Evolution in Orthoptera It 



The mating RF x S, (2), p. 65, could not have been other than 

 P/S^ X i^S which would produce 



P^ SS PS^ and S8^ 



1111 

 Pea Single Walnut Rose 



Another case is that of comb behaviour in experiments 33, 40 and 41, 

 (1), pp. 103, 106, 107. The $ in experiment 33 was well proven to 

 have been homozygous for the mo<lifying factor <E> which makes rose of 

 single (experiments 30-33) and her composition therefore should read 

 S^S*i> and the cT was single {SS). A pedigree arrangement of these 

 experiments would appear as follows : 



? .S'4>S<I) X SSj (expt. 33) 



20 



I 



h- 



Same ? 8 



1 



SS^ X SS<P (expt. 40) ? s SS^ x SS ^ (expt. 41) 



SS SS^ S#Sf* 



SS ss^ 



50 



48 

 Single 



46 



48 

 Rose 



These experiments 33, 40, and 41 of Bateson and Saunders are 

 exactly paralleled by matings (468) and (467) in Paratettix. 



If P and S represent bhe factors for pea and single respectively and 

 ^ the factor which modifies SS to make the two kinds of rose and PP 

 and PS to make the four kinds of walnut, a revision of Bateson's 

 16-square diagram, (2), p. 75, to correspond with the one for Paratettix 

 may be made : 



P* 



s^ 



s 



