vi CONTENTS 



PERIOD IV (1790-1858) - 89 



Characteristics of the period. Spreng-el and the 

 fertilisation of flowers. Cuvier and the rise of 

 palaeontology. Chamisso on the alternation of 

 generations in Salpa. Baer and the development of 

 animals. The cell-theory. The scientific investiga- 

 tion of the higher cryptogams. The enrichment of 

 English gardens. Humboldt as a traveller and a 

 biologist. Premonitions of a biological theory of 

 evolution. 



PERIOD V (1859 AND LATER) 124 



Darwin on the Origin of Species. Pasteur's experi- 

 mental study of microbes. 



CHRONOLOGICAL TABLE - - - 141 



THE SUB-DIVISIONS OF BIOLOGY - - 146 



BIBLIOGRAPHY - - 147 



INDEX- - 149 



