IV CONTENTS. 



Xo. 5. MAY, 1918. 



FASTEN, NATHAN. Spermatogenesis of the Pacific Coast Edible 



Crab, Cancer magister Dana 277 



SEIFRIZ, WILLIAM. Observations on the Structure of Protoplasm by 



Aid of Microdissection 307 



WHITNEY, D. D. Further Studies on the Production of Func- 

 tional and Rudimentary Spermatozoa in Rotifers 325 



SHULL, A. FRANKLIN. Effect of Environment upon Inherited 



Character of Ilydntina senta. .'. 335 



WARREN, DON C. The Effect of Selection upon the Sex Ratio in 



Drosophila ampelophila 351 



GOLDFARB, A. J. Effects of Ageing upon Germ Cells and upon 



Early Development. Part II 372 



Xo. 6. JUNE, 1918. 



SHULL, A. FRANKLIN. Effect of Environment upon Inherited 



Characters of Hydatina Senta 335 



WARREN, D. C. The Effect of Selection upon the Sex-Ratio in 



Drosophila ampelophila 351 



GOLDFARB, A. J. Effects of Aging upon Germ-Cells and upon 

 Early Development. Part II., Changes in ^Moderately Aged 

 Eggs and Sperm 372 



