ILLUSTRATIONS ix 



FIGURE PAGE 



35. Curve Showing the Daily Percentage Increments in 



Weight by Male Rabbits ..... 103 



36. Curve Showing the Daily Percentage Increments in 



Weight by Female Rabbits ..... 105 



37. Yearly Percentage Increments in Weight by Boys, 



Reckoned by M. Miihlmann .... 109 



38. Yearly Percentage Increments in Weight by Boys, 



after H. H. Donaldson . . . . .no 



39. Yearly Percentage Increments in Weight by Girls, 



Reckoned by M. Miihlmann . . . .113 



40. Yearly Percentage Increments in Weight by Girls, after 



H. H. Donaldson . . . . . .114 



41. Yearly Percentage Increments in Weight by Boys and 



Girls 116 



42. Ten Stages of the Developing Chick . . .119 



43. A Chick Removed from an Egg after an Incubation 



of Ten Days and Two Hours . . . .121 



44. Fourteen Stages of the Developing Rabbit - 4 . 123 



45. Percentage Increments up to Birth in Man by Lunar 



Months, after Miihlmann . . . ' . ^ .127 



46. Cells from the Mouth of the Salamander . . . 133 



47. Three Sections through a Rabbit Embyro of Seven 



and One-Half Days 136 



48A. Entamceba Histolytica, Highly Magnified . . 137 



488. Preserved Specimen of Entamtxba Histolytica . .13? 



49. Tertian Malarial Parasite ...... 139 



50. Trypanosoma Lewisi . . . . . . .140 



51. Stentor Cccruleus . . . . . 4 .141 



52. Various Kinds of Human Nerve Cells . . . 145 



