iv CONTENTS 



No. 3 OCTOBER 5 



Edmund B. Wilson. Studies on chromosomes. VIII. Observations on the 

 maturation-phenomena in certain Hemiptera and other forms, with 

 considerations on synapsis and reduction. Nine plates • 345 



Wayland M. Chester. Wound closure and polarity in the tentacle of 

 Metridium marginatum. Eight figures 451 



Max Morse. Artificial parthenogenesis and hybridization in the eggs of 



certain invertebrates 471 



No. 4 NOVEMBER 20 



"^ Edward B. Meigs. Contributions to the general physiology of smooth and 



striated muscle. Twenty figures 497 



A. R. Moore. Concerning negative phototropism in Daphnia pulex. One 



figure 573 



Jacques Loeb. The comparative efficiency of weak and strong bases in 



artificial parthenogenesis 577 



Wolfgang F. Ewald. On artificial modification of light reactions and the 



influence of electrolytes on phototaxis 591 



