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THE AMERICAN NATURALIST [Vol. LIII 



crossed (54, .56) to two restricted spot females (28, 13) 

 sired five self and five restricted spot. A restricted spot 

 male (8) crossed twice (9, 30) to a self female (20) sired 

 three self and seven restricted spot. A restricted spot 

 female (3) crossed (16) to a self male (6) produced six 

 self. Self by restricted spot therefore has produced sev- 

 enteen self and sixteen restricted spot, the expectation 

 if restricted spot is heterozygous. 



The restricted spot male (8) crossed (12, 33) to two 

 restricted spot females (25, 3) sired one self, three re- 

 stricted, and one moderate. This is in line with expecta- 

 tion if spotting is dominant, the moderate in this case 

 possibly representing the homozygote. 



The same restricted spot male (8) crossed (32) to a 

 solid- white (22) sired two solid-white and two completely 

 self. This is in line with the assumption that the white 

 female was homozygous for self, ss, and heterozygous 

 for color, Ww, or that spotting and white are both allelo- 

 morphic with self and that she was carrying self. The 

 male would then be ?r^;r, tr^ standing for restricted or 

 moderate spotting. 



Crosses invoh inu' uicatrr amounts of spotting may 



The self male (21) crossed (52) to a considerable spot 

 female (31) sired one self and two considerable. When 

 crossed (58) to a moderate spot (30) he sired three self 

 and two considerable. These results show that consid- 

 erable segregates from self and that a greater degree of 

 spotting may be produced from a less by crossing to self. 

 Modifiers are indicated. 



The same male was also crossed (57) to a considerable 

 (34) and sired two restricted. In this case modifiers 

 may have been assorted to produce restriction, but the 

 female (34) was derived from a cross (34) of a consid- 

 eral>le (24) by a restricted (3) each of which was known 

 to eari'v self. She may t In'iefore have been of composi- 

 tion If' )!■'■ : II- . nnn-h six.tiing, l)eing derived from her 

 consideral)le parent and /f little spotting, from her re- 



