174 



AN INTRODUCTION TO MODERN GENETICS 



2 

 O 



0. 



ACE 





%10 



•I 7 

 I' 



1 



B 



Extrusion ^^ 



20 30 



Time in Days 



W 



50 



Fig. 82. Genetic Control of the Rates of Developmental Processes. — 



k shows the deposition of pigment in the skins of caterpillars of different local 

 races of Lymantria (after Goldschmidt); 6 shows the darkening of the eyes in 

 Gammarus (after Ford and Huxley). 



