CHAPTER V

ADAPTATION FOR PROTECTION FROM ENEMIES 83

_Mollusca_: Clam, 83; Snail, 87; Squid, 89; Comparative Study, 91; Review and Library Exercise, 92. Comparative Study of Exoskeletons, 93; Protective Coloration, 94; Animal Associations, 96; Protective Habits and Powers, 98; Defensive Structures, 99; Thesis: "Adaptation for Protection," 99.