iv CONTENTS 



NO. 4 MAY 



11. T. Young. Some e.xporimeuts on protective coloration. Sixtj'-nine figures 457 



Theophilus 8. Painter. Contributions to the study of cell mechanics. I. Spiral aster.s. 



Seven text figures and two plates 509 



Asa a. Schaeffer. On the feeding habits of Ameba. Six plates 529 



Bradley M. Patten. The changes of the blowfly larva's photosensitivity with age. 



Four figures 585 



