No. 5. October, 1907 



PAGE 



Mary Blount. The Early Development of the Pigeon'' 's -Egg, 

 with Especial Reference to the Supernumerary Sperm Nuclei, 

 the Periblast and the Germ Wall 231 



J. Thomas Patterson. On Gastrulation and the Origin of the 



Primitive Streak in the Pigeon's Egg. — Preliminary Notice. 251 



T. H. Morgan and C. R. Stockard. The Effects of Salts 



and Sugar Solutions on the Development of the Frog' s Egg. .. 272 



L. H. Gregory. The Segmental Organ of Podarke obscura... 280 



C. R. Stockard. A Peculiar Legless Sheep 288 



No. 6. November, 1907 



D. D. Whitney. Artificial Removal of the Green Bodies of 



Hydra viridis 291 



N. Yatsu. A Note on the Adaptive Significance of the Sperm- 

 head in Cerebratulus 300 



Thomas H. Montgomery, Jr. On Parthenogenesis in Spiders.. 302 



S. J. Holmes. Rhythmical Activity in Infusoria 306 



D. H. Tennent. Further Studies on the Parthenogenetic Devel- 

 opment of the Starfish Egg 309 



Fernandus Payne. The Reactions of the Blind Fish, Amblyopsis 



spelaeus, to Light 317 



S. W. Williston. The Antennae of Diptera ; A Study in Phy- 

 togeny 324 



C. H. Turner. Do Ants Form Practical Judgments ? 333 



Julian Mast Wolfsohn. The Causation of Maturation in the 



Eggs of Limpets by Chemical Means 345 



