J. L. BROOKS 



95 



HL=234 



7 th GENERATION 



Figs. 3 and 4. Seasonal phenotypic variation in population of Daphnia 

 retrocurva Forbes in Bantam Lake, Conn., 1945. Series of camera lucida 

 drawings in each horizontal row depict characteristic shape of each size 

 group on date indicated. Head length (HL) and carpace length (CL) of 

 each given in microns. Diagonal lines trace development of newborn indi- 

 viduals of each sampling date. All have same magnification. 



