INDEX 



511 



Regulation in anman embryos witli spina 

 bifida defect. Asymmetrical 171 



Removal of the thymus glands in Raiia pip- 

 iens tadpoles. The results of earliest. .. . 189 



Reproduction. X. Head-frequency in Pla- 

 naria dorotocephala in relation to age, nu- 

 trition, and motor activity. Studies on 

 the dynamics of morphogenesis and in- 

 heritance in experimental 403 



SEA-URCHIN eggs. An experimental 

 study of cell-division. I. The phj'sical 

 conditions which determine the appear- 

 ance of the spindle in 211 



Sex recognition in frogs. The role of voice 

 and coloration in spring migration and. . . 325 



Shell characteristics in four species of the 

 genus Arcella. The relations between nu- 

 clear number, chromatin mass, cjtoplas- 

 mic mass, and , 1 



Spectral lights. II. The sensibility of Volvox 

 to wave-lengths of equal energy content. 

 Studies on the relative physiological value 

 of... 345 



Spina bifida defect. Asymmetrical regula- 

 tion in anuran embryos with 171 



Spindle in sea-urchin eggs. An experimental 

 study of cell-division. I. The physical 

 conditions which determine the appear- 

 ance of the 211 



Spring migration and sex recognition in frogs. 

 The role of voice and coloration in 32,^) 



Stewart, C. A., Jackson, C. M., and. The 

 eS'ects of inanition in the young upon the 

 ultimate size of the body and of the va- 

 rious organs in the albino rat 97 



Style in Mya arenaria after extraction. The 

 reformation of the crystalline , 259 



ScMNEH, Francis B. Geographic variation 

 and Mendelian inheritance 369 



TADPOLE larva. Amarouciuni pclluci- 

 dum (Leidy) form constcllatum (Ver- 

 rill). I. The activities and reactions of 

 the 239 



Tadpoles. The effects of hydrogen ion con- 

 centration and oxygen content of \vater 

 upon regeneration and metabolism of . . . . 461 



Tadpoles. The results of earliest removal of 

 the thymus glands in Rana pipiens 189 



Thymus glands in Rana pipiens tadpoles. 

 The results of earliest removal of the 189 



Thyroidless Bufo larvae. The parathyroid 

 glands of. 201 



Transplantation of the cerebral hemispheres 

 of Amblystoma. The 159 



'Twins.' An experimental study of an ami- 

 cronucleate Oxytricha. II. The forma- 

 tion of double-animals or 129 



VARIATION and Mendelian inheritance. 

 Geographic 369 



Voice and coloration in spring migration and 

 sex recognition in frogs. The role of 325 



Volvox to wave-lengths of equal energy con- 

 tent. Studies on the relative physiologi- 

 cal value of spectral lights. II. The sen- 

 sibility of 345 



WAVE-LENGTHS of equal energy con- 

 tent. Studies on the relative physio- 

 logical value of spectral lights. II. 



The sensibility of Volvox to 345 



Wilson, H. V., and Markham, Blackwell. 

 Asymmetrical regulation in anuran em- 

 bryos with spina bifida defect 171 



ZELENY, Charles. A change in the bar 

 gene of Drosophila melanogaster involv- 

 ing further decrease in facet number and 

 increase in dominance 293 



