IV CONTENTS OF VOLUME XVI. 



MORSE, MAX. The Autfftomy of the Hydranth of Tubularia 172 



BECKWITH, CORA JIPSON. Preliminary Report on the Early His- 

 tory of the Egg and Embryo of Certain Hydroids 183 



GUYER, MICHAEL F. On the Sex of Hybrid Birds 193 



WILSON, EDMUND B. The Female Chromosome Groups in Syro- 



mastes and Pyrrochoris 199 



TANNREUTHER, GEO. \V. Observations on the Germ Cells of Hydra. 205 



TANNREUTHER, GEO. W. Budding in Hydra 210 



No. 5. APRIL, 1909 



FOOT, KATHARINE, AND STROBELL, E. C. The Niicleoli in the 



Spermatoc\tcs and Germinal Vesicles of Euschistiis variolarius. 215 

 STOCK.ARD, CHARLES R. Inheritance in the " Walking-stick,' 1 '' 



Aplopus mayeri 239 



I )O\VMNG, ELLIOT R. The Connections of the Gonadial Blood 



Vessels and the Form of the Nepliridia in the Arenicolida... 246 

 GRAVE, B. H. Some Observations on the Habits of Pecten dislo- 



catus 259 



MORGAN, T. H. The Dynamic Factor in Regeneration 265 



No. 6. MAY, 1909 

 CHILD, C. M. The Regulatory Change of Shape in Planaria 



dorotocephala -77 



SHULL, CHARLES A. Some Abnormalities and Regeneration of 



Plciopods in Cambarns and Other Decapoda 297 



H o LMES, S. J . Sex Recognition in Cyclops 313 



RIDDLE, OSCAR. Our Knowledge of Melanin Color Formation 



and Its Bearing on the Mendelian Description of Heredity... 316 



