ll LIST OF ILLUSTRATIONS 



FACING PAGE 



Larvae and pupa of honeybee in their cells 253 



Internal organs of larval honeybee 253 



Pollination of an orchid (Cypripedimri) by a bumblebee . , 263 



Aristotle, 384-322 B.C 2 6 7 



Linnaeus at sixty, 1707-1778 269 



Cuvier, 1769-1832 27O 



William Harvey, 1578-1667 271 



Karl Ernst von Baer, 1792-1876 272 



Johannes Mtiller, 1801-1858 273 



Charles Darwin, 1809-1882 274 



Varieties of domestic pigeons * 294 



