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CONTENTS 



PART I 

 Morphological Types illustrating the Different Stages 

 of Organisation and the Trend of Vertebrate 

 Evolution 



PAGE 



1. The Vertebrate Type as contrasted with the Invertebrate . I 



2. Amphioxus, a primitive Chordate ..... 6 



3. Petromyzon, a Chordate with a skull, heart, and kidney . 20 



4. Scyllium, a Chordate with jaws, stomach, and fins . . 37 



5. Gadus, a Chordate with bone ...... 64 



6. Ceratodus, a Chordate with a lung ..... 80 



7. Triton, a Chordate with 5-toed limbs ..... 89 



8. Lacerta, a Chordate living entirely on land . . . .103 



9. Columba, a Chordate with wings . . . . .117 

 10. Lepus, a warm-blooded, viviparous Chordate . . . 133 



PART II 



Embryological Types illustrating the 

 Modes of Development 



11. The development of Amphioxus . 



12. The development of Rana (the Frog) . 



13. The development of Gallus (the Chick) 



14. The development of Lepus (the Rabbit) 



Different 



161 

 172 

 198 



227 



PART III 



Comparative Zoology of Chordates 

 Outline Classification of the main groups of Chordate animals 



showing the value and extent of comprehensive terms . 237 



15. The Blastopore 240 



16. The Embryonic Membranes ...... 247 



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