viii CONTENTS 



PAGE 



perhaps always, with variation of chemical composition 

 (Armand Gautier's investigations) ; Variation in Dimensions 

 and Experiments on the real cause of this Variation, Semper 

 and the Author ; Variation in Integuments, Form, Shape of 

 Fruits and Leaves, Flowers Penzig's Pflanzen- Teratologie 

 Skeleton, Muscles, Internal Organs and Viscera ; Sexuality 

 Neotenia 46 



LECTURE III 



The Facts of Natural or Spontaneous Variation (concluded) Phy- 

 siological or Chemical Variation Often exists where un- 

 suspected May be noticed in all parts of the Body, even 

 between very closely-related Forms Exists not only between 

 different Species, but between Varieties of same Species, 

 Individuals of same Variety, and even different ages of same 

 Individual Chemical Variation explains Racial Immunity to 

 peculiar Diseases This Chemical or Physiological Variation 

 in some cases of much higher import than any Morphological 

 Variation Chauveau's Experiments on Bacilhis anthracis 

 Physiological Differences between Brown and Green Frog 

 towards Poisons and Heat Tarchanoff's Experiments 

 Variation generally exists at all Ages, in all Groups of 

 Beings, at all Geological Epochs Sudden Variation ... 114 



LECTURE IV 



Second Group of Facts supporting Experimental Evolution ; Facts 

 of Domestication of Animals ; their Departure from the 

 original Wild Type as seen in the cases where the latter still 

 exists ; Much more might be done in this way, and many 



