116 
GENETICS IN RELATION TO AGRICULTURE 
and in separating tend to break apart at places, and in reuniting exchange 
Morgan has taken these two ideas and applied 
them to the results of the Drosophila investigations. The twisting of the 
chromatin material. 
55.1 
57.0 
59.5 
66.2 
Yellow, Spot 0.0 
White, Cherry, Eosin 
Abnormal 
Bifid 
Lethal II 
Lethal sb 
Club 16.6 
Lethal IIa 
Lethal sa 
Lethal II 
Vermilion 
34.7 
Miniature 35.0 
Furrowed 
40.0 
Sable 
52.0 
Rudimentary 
Bar 
Fused 
60.4 
Lethal se 
84,1 
90.0 
91.9 
Streak 
Dache 
Black 
Jaunty 
Purple 
Vestigial 
Curved 
Are 
Speck 
Morula 
0.0 
25.0 
40.0 
55.0 
73.0 
85.0 
Sepia 
+ Bent 
+ Eyeless 
Pink, Peach 
Kidney 
Ebony, Sooty 
Beaded 
Rough 
Fig. 54.—Plotted relations of factors in Drosophila ampelophila. 
chromosomes in synapsis is held to be the physical evidence of the known 
interchange of factors between chromosomes which takes place in crossing- 
over. Moreover, if the factors are the individual elements of the chro- 
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