IV CONTENTS. 



COLE, LEON J., AND LIPPINCOTT, W. A. The Relation of 

 Plumage to Ovarian Condition in a Barred Plymouth 

 Rock Pullet 167 



CHILD, C. M., AND HYMAN, L. H. The Axial Gradients in 



Hydrozoa 1 83 



No. 4. APRIL, 1919 

 LILLIE, RALPH S., AND JOHNSTON, EARL N. Precipitation 



Structures Simulating Organic Growth, II 225 



PACK, DEAN A. Two Ciliata of Great Salt Lake 273 



MEYER, ARTHUR WILLIAM. Uterine, Tubal and Ovarian 



Lysis and Resorption of Conceptuses . 283 



No. 5. MAY, 1919 



YOUNG, R. T. The Degeneration of Folk Glands and Cells 



in Cestodes 309 



YOUNG, R. T. Association of Somatic and Germ Cells in 



Cestodes 312 



FAUST, ERNEST CARROLL. The Excretory System in Digenea, 



I- 315 



FAUST, ERNEST CARROLL. The Excretory System in Digenea, 



II 322 



FAUST, ERNEST CARROLL. The Excretory System in Digenea, 



HI 340 



Twenty-First Annual Report of the Marine Biological Labora- 

 tory for the Year 1918 345 



No. 6. JUNE, 1919 



THOMPSON, CAROLINE BURLING. The Development of the 



Castes of Nine Genera and Thirteen Species of Termites. 379 



SEILER, J. Researches on the Sex-chromosomes of Psychidce 



(Lepidoptera) 399 



ALLEN, BENNET M. The Relation of the Pituitary and 

 Thyroid Glands of Bufo and Rana to Iodine and Meta- 

 morphosis 405 



TANNREUTHER, GEORGE W. The Migration of Reproductive 



Organs from Parent to Buds in Hydra 419 



COLLETT, M. E. Resistance of Cilia to Cytolytic Agents. . . . 424 



