iv CONTENTS 



No. 5. APRIL, 1906 



PAGE 



ESTHER F. BYRNES : Two Transitional Stages in the Development of 



Cyclops signatits, var. coronatus 193 



T. H. MORGAN : The Male and Female Eggs of Phylloxerans of the 



Hickories 201 



CHAS. W. HARGITT : The Organization and Early Development of the 



Egg of Clava leptostyla Ag. 207 



PHILIP B. HADLEY : Regarding the Rate of Growth of the American 



Lobster 233 



T. B. ROBERTSON : Note on the Influence of Temperature upon the Rate 



of the Heart-beat in a Crustacean ( Ceriodaphnia) 242 



L. B. SEELY : Two Distomes 249 



No. 6. MAY, 1906 



INEZ L. WHIPPLE : The Ypsiloid Apparatus of Urodeles 255 



FRANCIS B. SUMNER : The Osmotic Relations Between Fishes and their 



Surrounding Medium (Preliminary Note} 298 



