CONTENTS. 1 1 



CHAPTER XIV. 



PAGE 



LOWER ANIMALS 217 



Basis of comparison Size and activity of different 

 animals Anthropoid apes : The orang-utan and chim- 

 panzee Horses : English thoroughbreds American trotters 

 Testimony of horse breeders Breeding from immature 

 animals The fastest trotters in the world The greatest 

 sires of speed Transmission by sex in horses Relation 

 of age and training in sires Reproduction earlier in 

 common than in blooded horses Cattle: Early breeding 

 Birth-ranks of famous bulls Average for ordinary 

 cattle Dogs and sheep Rabbits and squirrels ^Hibernat- 

 ing squirrels The beaver Seals and deer The elephant 

 and hippopotamus Guinea pigs White njice Common 

 fowl Crows Parrots Bee Moth Coccus Ant. 



CHAPTER XV. 

 REPRODUCTION, PUBERTY AND LONGEVITY 232 



Lamarck's laws and their proof The factors of use, 

 how combined Diagram of animals by the factor of age 

 Proportion of life during which developing activity con- 

 tinues Relative variations of time and activity Time a 

 stimulus for mental activity The rise of races Time 

 between generations increased by delay of puberty 

 Puberty affected by climate and mode of life Age of 

 puberty at different places Variations by latitude 

 Adolescence a period of acute sexuality Early puberty 

 caused by congenital acute sexuality Degenerate and 

 luxurious classes come early to puberty Early reproduc- 

 tion and length of life Length of life of different classes 

 Longevity and mental aptitudes Relation of birth- 

 rank to longevity Selection eliminated Longevity of 

 different sons of the same family Longevity and birth- 

 ranks of brothers and sisters Birtht-ranks and ex- 



