CONTENTS 



XXXIV. A study of how a live fish is fitted for the life it leads 195 

 * XXXV. A study of some of the relations of fishes to their food 



supply . . : . .... .... . 199 



XX XVI. The artificial propagation of fishes . ... . 202 



THE STUDY OF THE FROG AS AN INTRODUCTION 

 TO MAN 



XXXVII. Some adaptations in a living frog, as an introduction 



to the study of man . . . . ? . 204 

 XXXVIII. A study of the development of the frog . . 207 



BIRDS IN THEIR RELATION TO MAN 



XXXIX. A study of some adaptations and reactions in birds . 211 

 XL. How birds are of economic importance . . . 213 



THE HUMAN BODY AS A MACHINE 



XLI. A study of man as a vertebrate, as compared with a 



frog . . .218 



FOODS AND DIETARIES 



XLII. A study of food values and diets . . . . 226 



XLIII. A study of some forms of food adulteration, and 



some simple means of detecting them . . . 251 



XLIV. A study of some medical frauds . . . . 255 



ADAPTATIONS FOR DIGESTION, CIRCULATION, AND 

 ABSORPTION OF FOODS 



XLV. A study of the digestive system of a frog in order bet- 

 ter to understand that of man . '. . . 267 

 XLVI. How foods are chemically prepared for absorption 



into the blood . - ...;."'.; . . . . 271 



XL VII. A study of where and how digested foods pass into 



the blood (absorption) . ... . . 277 



XLVIII. To study the general composition of blood . . 281 



'. XLIX. A study on the circulation of the blood . . . 282 



L. Some changes in the composition of the blood . . 289 



