MUTATIONS IN EYE-COLOR OF DROSOPHILA 



329 





R d" (out of Pink 9 X Red tf) X P 9. Dry 6o«fe. 



9 



cf 



Total. 



Bed 



Pink 



Red. 



Pink 



Count 1 

 Count 2 

 Count 3 

 Count 4 

 Count 5 

 Count 6 

 Count 7 





14 

 17 

 10 

 19 

 20 

 9 

 5 



8 



8 



13 



17 



12 



12 



10 



14 



17 



39 



12 



7 



3 1 



7 



11 



14 

 10 

 15 

 28 

 9 

 13 



Red. 



22 



Pink 

 19 



Proportion of 

 Red to Pink. 



34 



27 



22 



22 



33 



25 



59 



45 



21 



16 



12 



16 



1.16 : 1 



1.25:1 

 1.00:1 

 132 : 1 

 1.31 : 1 

 0.76 : 1 

 0.75 : 1 



At the time the count began, the bottles were covered with cloth, in order 

 that the contents might dry out faster. The first counts, therefore, represent 

 average conditions, but towards the end the bottles had become very dry. The 

 entire count in these, and in the two preceding tables, covered about ten days. 

 These last two tables seem also to show a constant change in the direction of 

 relatively more Pinks. 



Other conditions than moisture or dry 



must be responsible for these 



results. In order to get data for comparison the early records of two 



bottles, selected at random 



given 



the next tables. These bottles also 



became drier towards the end as no fresh food was added. The first table 

 seems to show a change, as before, but not so great. In the second, the change 

 is also seen (if we reject the last two counts) but is not so marked. It is quite 

 possible, therefore, that while dryness may make the conditions less favorable 

 for the Pinks, it is evident that the change in ratio may be explicable on the 

 assumption that the Pinks develop more slowly than the Reds. 



Count 1 

 Count 2 

 Count 3 

 Count 4 

 Count 5 

 Count 6 



Red. 



6 

 21 

 75 



8 

 29 

 32 



9 



>/ 



Pink 



3 



4 

 38 



7 

 27 

 16 



Red. 



7 



21 

 66 

 12 

 20 

 30 



c? 





Pink. 



4 



10 



28 



7 

 16 

 26 



Red. 



13 



42 

 141 

 20 

 49 

 62 



Total. 



Pink. 



7 



14 



66 

 14 



43 

 42 



Proportion of 

 Red to Pink. 



2.6 :1 



2.13:1 

 1.43 : 1 

 1.14:1 

 1.47 : 1 



Count 1 

 Count 2 

 Count 3 

 Count 4 

 Count 5 

 Count 6 



Count 7 



Red. 



8 

 6 

 12 

 48 

 23 

 12 

 18 



9 



Red 9 (out of P 9 XR o") X Pink 



Pink 



7 



4 



4 



28 



19 



4 



7 



Red 



9 



5 



12 



47 

 26 

 12 

 13 



<? 



Pink 



1 

 1 



8 

 31 

 13 



3 



7 



Red. 



17 

 11 

 24 



95 

 49 

 24 

 31 



Total. 



Pink 



8 

 5 



12 



59 

 32 



7 



14 



■ 



Proportion of 

 Red to Pink 



2.15 : 1 



2 



:1 



1.6 :1 

 1.53:1 



2.6 :1 



The different ratios of Reds to Pinks seen in these and my former experiment 





