CHAPTER III

[The Connection between Structure and Function] 44

Protozoa: [A Study of the Cell], 44; [Comparative Study], 48; [Review and Library Exercise], 49; [Sponges], 51; [Review and Library Exercise], 53. Cœlenterates: [Hydra], 54; [Comparative Study], 58; [Review and Library Exercise], 59. Worms: [Living Earthworm], 61; [External Morphology], 64; [Internal Morphology], 64; [Microscopic Anatomy], 66; [Summary], 68; [Review and Library Exercise], 70; [Connection between Structure and Function], 72.

CHAPTER IV

[Adaptation to Surroundings] 73

Crayfishes: [Living Crayfish], 73; [Morphology], 75; [Summary], 79; [Review and Library Exercise], 81.

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.