CONTENTS 



Xo. 1. DECEMBER, 1917 



C. M. Child. Differential susceptibility and differential inhibition in the de- 

 velopment of polychete annelids. Fifty-seven figures (10 plates) 1 



Grace P. Hays. A case of a syndactylous cat. Sixteen figures 65 



Caroline Burling Thompson. Origin of the castes of the common termite, 



Leucotermes flavipes Kol. Forty-two figures (8 plates) 83 



Robert T. Hance. The diploid chromosome complexes of the pig (Sus scrofa) 



and their variations. Ten plates and five text figures 155 



Harold R. Hagan. Observations on the embrj^onic development of the mantid 



Paratenodera sinensis. Two text figures and three plates 223 



B. H. .Grave. Zeugophora scutellaris (Suffr.) Twelve figures (2 plates) 245 



H. M. KiNGERY. Oogenesis in the white mouse. Fifty-two figures (5 plates). 261 

 Grace Medes. A study of the causes and the extent of variations in the larvae 

 of Arbacia punctulata. One hundred and fifty-two figures 317 



Xo. 2. .AIARCH, 1918 



H. V. Neal. The history of the eye muscles. Twenty figures 433 



A. Franklin Shull. Cell inconstancy in H5-datina senta 455 



William A. Kepner and John S. Lawrence. The ej-e of pol3^c5^stis goettei. 



Five figures (one plate) .' 465 



William A. Kepner and W. J. Scott. Cushion cells of the pharynx of Prorhj-n- 



chus applanatus Kennel. One text figure and one plate 475 



Wara Nakahara. Studies of amitosis: Its physiological relations in the adi- 

 pose cells of insects, and its probable significance. Thirty-six figures (six 

 plates) 483 



A. C. Walton. The oogenesis and early embryology of Ascaris canis Werner. 

 Nine plates and one text figure 527 



Francis Marsh Baldwin. Pharyngeal derivatives of Amblystoma. Forty-six 

 figures 605 



