iv CONTENTS. 



PAC;E. 



GARY N. CALKINS : Studies on the Life-History of Protozoa. 

 III. , The Six Hundred and Twentieth Generation of 

 Paramoecium Can datum 192 



K. FOOT AND E. C. STROBELL : Further Notes on the Cocoons of 



Allolobophora fa'tida 2 06 



C. O. WHITMAN: A Biological Farm. 214 



H. S. JENNINGS AND C. JAMIESON : Studies on Reactions to Stimuli 

 in Unicellular Organisms. X. , The Movements and Reac- 

 tions of Pieces of Ciliate Infusoria 225 



A. L. TREADWELL : Notes on the Nature of " Artificial Partheno- 

 genesis ' ' /;/ the Egg of Podarke obscura 235 



ROBERT YERKES : Habit formation in the Green Crab, Carcinus 



granulatus 241 



No. 6. NOVEMBER, 1902 



HELEN DEAN KING: The Follicle Sacs of the Amphibian Ovary. 245 

 WM. E. RITTER : The Movements of the Enteropneusta and the 



Mechanism by which they are Accomplished. 255 



CHARLES RUSSELL BARDEEN : Embryonic and Regenerative De- 

 velopment in Planarians 262 



R. M. STRONG: A Case of Abnormal Plumage 289 



JACQUES LOEB : Maturation, Natural Death and the Prolongation 

 of the Life of Unfertilized Starfish Eggs (Asterias Forbesii} 

 and their Significance for the Theory of Fertilization 295 



