THE AMEBIC AN NATURALIST [Vol. LII 



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>^ Zygotes: Phenol 







Illustrative. 







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case may be. A word within a test-tube circle names the color 

 of the reaction-product, which color is the index or analog of the 

 somatic working out of its accompanying genetic formula of the 



Instructions for performing the experiment illustrative of 

 each ratio-modification are found in detail in the drawing for 

 the selected case. The chemicals representing gene "A" and 

 gene "B" and the substratum are, as indicated, poured into the 

 test-tubes representing the F 1 female and the F L male gametes. 

 Each gamete-holding test-tube should contain approximately 20 

 e.c. of the appropriate genes and substratum. Of this mixture 

 4 c.c. represent 1 gamete ; and 1 such gamete is to be poured into 

 each one of the 4 zygote-holding test-tubes, directly below or 

 directly to the right, as the case may be, of particular gamete- 

 holding test-tube, following the checker-board method. Thus 

 each of the 16 zygote test-tubes will contain chemicals appro- 



