CONTENTS 



No. I — February, 1907 

 Charles Russell Bardeen 



Abnormal Development of Toad Ova Fertilized by Spermatozoa Fxposed 

 to the Roentgen Rays. With Five Plates i 



William B. Herms 



An Ecological and Experimental Study of Sarcophagidas with Relation to 

 Lake Debris. With Seven Figures 45 



Sara White Cull 



Rejuvenescence as the Result of Conjugation 85 



George Lefevre 



Artificial Pathenogenesis in Thalassema Mellita. With Six Plates gi 



Jacques Loeb 



Concerning the Theory of Tropisms 151 



Frank W. Bancroft 



The Mechanism of the Galvanotropic Orientation in Volvox 157 



No. 2 — June, 1907 

 Charles R. Stockard 



The Influence of External Factors, Chemical and Physical, on the 

 Development of Fundulus Heteroclitus. With Seventeen Figures 165 



O. C. Glaser 



Movement and Problem Solving in Ophiura Brevispina. With Five 

 Figures 203 



Isabel McCracken 



Occurrence of a Sport in Melasoma (Lina) Scripta and its Behavior in 

 Heredity. With One Plate 221 



Ross Granville Harrison 



Experiments in Transplanting Limbs and their Bearing upon the Prob- 

 lems of the Development of Nerves. With Fourteen Figures 239 



E. G. Spaulding 



The Energy of Segmentation. An Appplication of Physical Laws to 

 Organic Events 283 



