CONTENTS xi 



PAOE 



GILLS (continued) 



of Cyclostomes ". . 352 



of Fishes 355 



of Amphibians . '. . . 358 



II. SWIM-BLADDER AND LUNGS 361 



1. SWIM-BLADDER 361 



2. LUNGS -' . 362 



Air-Tubes and Larynx 364 



of Amphibians 366 



of Reptiles 369 



of Birds ' . , 370 



of Mammals ...'.. '371 



The Lungs 377 



of Dipnoans 377 



of Amphibians :...... 377 



of Reptiles 379 



of Birds 382 



of Mammals ; . 387 



CCELOME 388 



SEROUS MEMBRANES . . 388 



ABDOMINAL PORES - 389 



H. ORGANS OF CIRCULATION ... 393 



General Description and Development 393 ' 



Heart, together with origin of Main Vessels 400 



of Fishes . . 400 



of Amphibians 403 



of Reptiles 407 



of Birds and Mammals 411 



Arterial System 414 



Venous System 419 



of Amphioxus 419 



of Fishes 419 



of Amphibians 426 



of Amniota 428 



Retia Mirabilia 431 



Lymphatic System 432 



MODIFICATIONS FOR THE INTER-UTERINE NUTRITION 



OF THE EMBRYO : FCETAL MEMBRANES 436 



1. Anamnia 436 



2. Amniota 437 



