CONTENTS OF VOLUME XVII. 



No. i. JUNE, 1909 

 Eleventh Report of the Marine Biological Laboratory i 



No. 2. JULY, 1909 



LILLIE, FRANK R. Karyokinetic Figures of Centrifuged Egg ; 



an Experimental Test of the Center of Force Hypothesis 101 



WALLACE, LOUISE B. The Spermatogenesis of Agalena ncevia... 120 

 TURNER, C. H. The Mound of Pogonomyrmex badius Latrl. and 



its Relation to the Breeding Habits of the Species 1 6 1 



NEWMAN, H. H. Contact Organs in the Killifishes of Woods 



Hole 170 ^ 



No. 3. AUGUST, 1909 



NEWMAN, H. H., and PATTERSON^, J. THOS. A Case of Normal 

 Identical Quadruplets in the Nine-banded Armadillo, and its 

 Bearing on the Problems of Identical Twins and of Sex 

 Determination 181 



LILLIE, RALPH S. The General Biological Significance of Changes 

 in the Permeability of the Surface Layer or Plasma-membrane 

 of Living Cells 188 



SMALLWOOD, W. M. A Reexamination of the Cytology of Hydrac- 



tinia and Pennaria 209 



WILLISTON, S. W. New or Little Known Permian Vertebrates. 



Pariotichus. . 241 



No. 4. SEPTEMBER, 1909 



ANDREWS, E. A. Sperm -transfer Organs in Cambaroides 257 



PEARL, RAYMOND, and CURTIS, MAYNIE R. Studies on the 



Physiology of Reproduction in the Domestic Fowl 271 r 



WOODRUFF, LORANDE Loss. Further Studies on the Life Cycle 



of Paramecium 287 * 



RICHARDS, A. On the Method of Cell Division in T<znia 309 



iii 



