LIST OF ILLUSTRATIONS. 



PLATE I. (Haeckel.) Fig. A, tortoise (IV weeks). Fig. B, chick (IV days). 



" E, tortoise (VI weeks). " F, chick (VIII days). 



PLATE II. (Haeckel.) Fig. C, dog (IV weeks). Fig. D, man (IV weeks). 



" G, dog (VI weeks). " H, man (VIII weeks). 



Plates I. and II., facing page 920. 



PLATE III. (Erdl.) Fig. 1, human embryon, at the ninth week. 



" 2, human embryon, at the twelfth week. 

 Plate III., facing page 922. 



PIOtTBB PAGE 



1. Human red blood-corpuscles. (United States Army Medical Museum.) 7 



2. Human red blood-corpuscles arranged in rows, with two white corpuscles, or leucocytes . . 7 



3. Blood-corpuscles of the frog. (United States Army Medical Museum.) 8 



4. Artificial capillary filled with a sanguineous mixture, seen under a micrometer. (Malassez.) 11 



5. Human blood-corpuscles, showing post-mortem alterations 11 



6. Human red and white blood-corpuscles 15 



7. Crystallized haemaglobine. (Gautier.) 18 



8. Fibrinous clot. (Robin.) 30 



9. Harvey's observations on the flow of blood in the veins. (Harvey.) 33 



10. Diagram of the four cavities of the heart. (Bernard.) 34 



11. Heart in situ. (Dalton.) 35 



12. Heart, anterior view. (Bonamy and Beau.) 36 



13. Left cavities of the heart. (Bonamy and Beau.) 37 



14. Right cavities of the heart. (Bonamy and Beau) 38 



15. Muscular fibres of the ventricles. (Bonamy and Beau.) 39 



16. Anastomosing muscular fibres of the heart. (Morel.) 39 



17. Valves of the heart. (Bonamy and Beau.) 40 



18. Diagram showing shortening of the ventricles during systole 43 



19. Cardiograph. (Chauveau and Marey.) 45 



20. Small artery from the mesentery of the frog. (United States Army Medical Museum.) . . 66 



21. Apparatus for showing the action of the elasticity of the arteries. (Marey.) 69 



22. Sphygmograph of Marey ^2 



23. Sphygmograph applied to the arm, with traces of the pulse. (Marey.) *72 



24. HaDmadynamometer of Poisseuille ^ 



25. (A) Cardiometer of Magendie. (B) Compensating instrument of Marey f6 



26. Chauveau's instrument for measuring the rapidity of the flow of blood in the arteries. . . 79 



27. Capillary blood-vessels. (Eberth.) 81 



28. Small artery, and capillaries. (United States Army Medical Museum.) 83 



29. Web of the frog's foot. (Wagner.) 85 



30. Circulation in the web of the frog's foot. (Wagner.) 85 



31. Small artery and capillaries from the lung of the frog. (United States Army Medical 



Museum.) 86 



