XVI CONTENTS. 



PAOB 



SUMMARY 489 



JB. The Development of the Organ of Hearing .... 490 

 () The Development of the Otocyst into the Labyrinth . 4<)1 

 (J) Membranous Ear-Capsule into 



the Bony Labyrinth and the 

 Perilyrrphatic Spaces . 498 



0) ,. ,, Middle and External Ear . . 505 



SUMMARY 510 



C. The Development of the Organ of Smell 511 



SUMMARY 518 



III. THE DEVELOPMENT OP THE SKIN AND ITS ACCESSORY ORGANS 520 



(a) The Skin 520 



(J) Hair 522 



O) Nails 526 



(d) Glands of the Skin 528 



SUMMARY . 531 



CHAPTER XVII. 

 THE ORGANS OF THE INTERMEDIATE LAYER OR MESENCHYME 538 



I. THE DEVELOPMENT OP THE BLOOD-VESSEL SYSTEM . . . 542 



A. The first Developmental Conditions of the Vascular System . 542 



O) Of the Heart 542 



(&) Vitelline Circulation, AUantoicand Placental Circulation 549 



B. The further Development of the Vascular System up to the 



Mature Condition . 553 



(a) The Metamorphosis of the Tubular Heart into a Heart 



with Chambers 553 



(i) The Development of the Pericardial Sac and the Dia- 

 phragm 566 



(c) Metamorphoses of the Arterial System .... 570 



(d} Venous ., .... 577 



SUMMARY 588 



II. THE DEVELOPMENT OF THE SKELETON 593 



A. The Development of the Axial Skeleton 593 



() The Development of the Vertebral Column . . .596 



(&) Head -Skeleton .... 603 



I. Bones of the Cranial Capsule . . . . 619 



II. Visceral Skeleton 622 



(c) Concerning the Relation of the Head-Skeleton to the 



Trunk-Skeleton 627 



D. The Development of the Skeleton of the Extremities * . 635 



O) Pectoral and Pelvic Girdles 638 



(&) Skeleton of the Free Extremity 640 



(c) Development of the Joints 644 



SUMMARY 647 



APPENDIX TO LITERATURE 653 



INDEX . 659-70 



