CONTENTS OF VOLUME XXXIII. 



No. i. JULY, 1917. 



Nineteenth Annual Report of The Marine Biological Laboratory I 

 PATTERSON, J. L., AND PORTER, LELIA T. Studies on the Biology 

 of Paracopidosomopsis.- II. S per mato genesis of Males Reared 



from Unfertilized Eggs 38 



WOODRUFF, LORANDE Loss. Rhythms and Endomixis in Various 



Races of Param&ciwn aurelia 51 



No. 2. AUGUST, 1917. 

 PATTERSON, J. T. Studies on the Biology of Paracopidosomopsis. 



///. Maturation and Fertilization 57 



WULZEN, ROSALIND. Some Chemotropic and Feeding Reactions of 



Planaria maculata 67 



SWINGLE, W. W. The Accessory Chromosome in a Frog Possessing 



Marked Hermaphroditic Tendencies 70 



LOEB, LEO. The Experimental Production of Hypotypical Ovaries 



through Under-feeding. A Contribution to the Analysis of 



Sterility 91 



SWINGLE, W. W. Experiments with Feeding Thymus Glands to 



Frog Larvce 116 



No. 3. SEPTEMBER, 1917. 



LILLIE, RALPH S. The Formation of Structures Resembling Or- 

 ganic Growths by Means of Electrolytic Local Action in Metals, 

 and the General Physiological Significance and Control of this 

 Type of Action 135 



LOEB, LEO. The Concrescence of Follicles in the Hypotypical 



Ovary 187 



COWDRY, N. H. Comparison of Mitochondria in Plant and Ani- 

 mal Cells 196 



No. 4. OCTOBER, 1917. 

 TOWER, WILLIAM LAWRENCE. Inheritable Modification of the 



Water Relation in Hibernation of Leptinotarsa decem-lineata . . 229 

 MOORE, CARL R. On the Capacity for Fertilization after the Initia- 

 tion of Development 258 



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