THE DEVELOPMENT OF THE BLOOD VESSELS IN THE 



FEOG. 



By A. Milnes Maeshall, M.D., F.R.S., Beyer Professor of Zoology 



in the Owens College ; and 



Edward J. Bles, of the Owens College. 



[With Plates XIII., XIV., and XV.] 



CONTENTS. 



Page 



Introduction 186 



Historical Account 187 



The Early Development of the Heart 190 



The Heart and Blood Vessels in 4^ mm. Tadpoles 196 



The Heart and Blood Vessels in 5 mm. Tadpoles 208 



The Heart and Blood Vessels in 6J mm. Tadpoles 215 



The Heart and Blood Vessels in 9 mm. Tadpoles , 222 



Tli'' Heart and Blood Vessels in 12 mm. Tadpoles 231 



The Heart and Blood Vessels in 21-23 mm. Tadpoles 248 



The Heart and Blood Vessels during the Metamorphosis 252 



The Heart and Blood Vessels in First Year's Frogs 257 



-Mm mi ry 259 



Description of the Figures 264 



