iv CONTENTS OF VOLUME XVIII. 



Payne, Fernandus. The Chromosomes of Acholla multispinosa . . . . 174 



WiEMAN, H. L, The Pole Disc of Chrysomelid Eggs 180 



Payne, Fernandus. Forty-nine Generations in the Dark 188 



Mast, S. O. Do Blow Fly LarvcB Respond to Gravity? 191 



Cole, Leon J. Peculiar Habitat of a Pycnogonid {Endeis spinosus) 

 new to North America, with Observations on the Heart and Circu- 

 lation 193 



Smith, Bertram G. The Structure of the Spermatophores of Amhy- 



stoma punctatum 204 



No. 5. April, 1910. 



Twelfth Annual Report of the Marine Biological Laboratory 213 



KiRKHAM, William B. Ovulation in Mammals, with Special Refer- 

 ence to the Mouse and Rat 245 



Cole, Leon J. Description of an Abnormal Lobster Cheliped 252 



Harvey, E. Newton. Methods of Artificial Parthenogenesis ..... 269 



Heath, Harold. Pelagosphcera, a Larval Gephyrean 281 



No. 6. May, 1910. 

 Tower, Wm. L. The Determination of Dominance and the Modifica- 

 tion of Behavior in Alternative (Mendelian) Inheritance, by Condi- 

 tions Surrounding or Incident upon the- Germ Cells at Fertilization. 285 



