CONTENTS. 



No. 2. — December, 1887. 



PAGE 



I. C. O. Whitman. 



The Kinetic Phenomena of the Egg dur- 

 ing Maturation and Fecundation (^Ooki- 

 nesis) ....... 227-253 



II. Dr. W. B. Scott, of Princeton College, N.J. 



The Embryology of Petromyzon . . 253-310 



III. Dr. Henry Orr, Princeton, N.J. 



A contribution to the Embryology of the 



Lizard ....... 311-372 



IV. Dr. H. F. Osborn, Princeton College, N.J. 



The Eoetal Membranes of the A/arsupials, 373~382 



V. George W. and Elizabeth G. Peckham, Mil- 

 waukee, Wis. 



Some Observations on the Mental Powers 



of Spiders 383-419 



