CONTENTS IX 



CHAPTER VI 



THE COLOURS OF CRUSTACEA AND ECHINODERMA 



Nature of Colours of Crustacea — Colour Variation — Pigments of 

 Crustacea: (I) Lipochromes, (2) Soluble Blues — Relations of 

 the Two — General Characters of Pigments — The Colours of 

 Echinoderma : (l) Star-fishes, (2) Brittle-stars, (3) Sea-urchins, 

 (4) Crinoids, (5) Holothurians — Pigments of Five Classes — 

 Relations to those of Crustacea . . Page 117 



CHAPTER Vn 



THE COLOURS OF THE LEPIDOPTERA 



Insect Coloration and its General Relation to Physiology — Pigments 

 of Caterpillars — Intrinsic and Derived Pigments — Mr. Poulton's 

 Experiment — Meaning of Derived Pigments — Other Characters 

 of the Coloration of Caterpillars — Colours of Butterflies, Pig- 

 mental and Optical Colours — The Pigments of the Pieridaa — 

 Pigments of other Butterflies — Origin of the Pigments of Butter- 

 flies — Contrast between the Pigments of Butterflies and those of 

 Caterpillars — Pigments and Mimicry . 138 



CHAPTER Vni 



THE COLOURS OF INSECTS IN GENERAL AND OF SPIDERS 



Optical and Pigmental Colours in Insects — Colours of the different 

 Orders of Insects — Colours and Pigments of Orthoptera — Optical 

 Colours of Neuroptera — Coloration of Beetles — Pigments of 

 Hemiptera — Colour Resemblances between Diptera and Hymen- 

 optera — Contrast between Coloration of Lepidoptera and other 



