CONTENTS. 
CHAPTER IX. 
BIONOMICS, 
Physical Relations 
Coral Islands 
Organic Relations a 
Commensalism and Symbiosis ... 
Endoparasitism mes 
Protective Resemblance er mer. 
CHAPTER X. 
HEREDITY AND DESCENT. 
Heredity and Variation ... 
Evolution ... 2 
Sexual Selection ... 
Part II. 
CHAPTER XI. 
PROTOZOA. 
Amoeba 
Paramcecium 
Vorticella ... 
Gregarina .. 
The Preinrod : 
The Gymnomyxa and Cerkets 
CHAPTER XII. 
PORIFERA. 
Sycandra ... 
The Porifera 
x1 
80 
81 
82 
103 
107 
