• •• 



nn CONTENTa 



PAOR 



Lizard .like Pttrent-form (Protanmion) . — First Formation of the 

 Allantois and of the Amnion. — Branching of the Amnion Animab 

 in Two Lines : on the one side, Beptiles (and Birds), on the other 

 side, MammalB ... ... ... m* m* ••• 107 



CHAPTER XIX. 



THE PEDIGREE OF MAN. 



lY. From the Fbimxtiyb Mammal to thi Apb. 



The Mammalian Character of Man. — Common Descent of all Mammals 

 from a Single Parent-form (Promammalian). — Bifurcation of the 

 Amnion Animals into Two Main Lines : on the one side, Rep- 

 tiles and Birds, on the other, Mammals. — Date of the Origin of 

 Mammals : the Trias Period. — The Three Main Groups or Sub- 

 classes of Mammals : their Genealogical Relations. — Sixteenth 

 Ancestral Stage : Gloacal Animals (IToTto^r&mata, or Omithodelphia), 

 —The Extinct Primitive Mammals (Promo/mmaUa) and the Extant 

 Beaked AnimitlH (Omithostoma) . — Seventeenth Ancestral Stage: 

 Pouched Animals {McurtupiaUa, or Didelphia). — Extinct and Extant 

 Pouched Animals. — Their Intermediate Position between Mono- 

 tremes and Placental Animals. — Origin and Structure of Placental 

 Animals (PlacentaUoj or MonodeVphia). — Formation of the Pla- 

 centa. — The Deciduous Embryonic Membrane (Decidua). — Group 

 of the Indecidtia and of the Decid/uata. — The Formation of the 

 Decidua (vera, serotina, reflexa) in Man and in Apes. — Eighteenth 

 Stage: Semi-apes (ProBimice). — Nineteenth Stage : Tailed Apes 

 {Menocerea). — Twentieth Stage : Man-like Apes (Anthropoides), — 

 Bpeeohleu and Speaking Men (Mali. Hominet) ,„ .^ 140 



CHAPTER XX. 



SUB raSTOBT OF THE EVOLUTION OF THE EPIDERMIS AND 



THE NERVOUS SYSTEM. 



Animal and Vegetative Organ.systems. — Original Relations of these to 

 the Two Primary Germ-layers. — Sensory Apparatus. — Constituents 

 of Sensory Apparatus : originally only the Exoderm, or Skin-layer ; 

 afterwardfl, the Skin.oovering specialized from the Nerve-system. 

 — ^Doable Function of the Skin (as a Covering and as Organ of 



