CONTENTS. 



PAET I.-INYERTEBEATE ANIMATES. 



Page 



Meaning of the Term Zoology 1 



Structure, the Basis of Correct Classification 2 



AnimaU arranged in four primary Groups 3 



EADIATA, OK EAYED Ai^IMALS. 



Meaning of the Term 3 



Group divided into four Classes 4 



CLASS I.— INFUSORIA, or INFUSOEY ANIMALCULES. 



Their Size and Distribution 5 



Arrangement in two Divisions — Advantage of Scientific Terms — 



Polygastrica, or Many-Stomached 6 



Experiments of Ehrenberg — Cilia 7 



Rotifera, or "Wheel-bearing — Their Tenacity of Life — Different Modes 



of Reproduction among the Infusoria 8 



Physical Changes effected through their Agency 10 



CLASS IL— ENTOZOA, on INTESTINAL WORMS. 



'Their Abodes — Variety of Structure — The Tape-worm 12 



Jlultitude of Ova in another Species — Tliese Creatures not produced 



by Equivocal Generation — Perfection of their Structure 13 



CLASS III ZOOPHTTA, ok POLYPES. 



Meaning of these Terms 14 



The Class subdivided into four Orders 15 



Order I. — Hydkoida, or those resejiblino the Hydka 15 



The Fresh-water Hydra 15 



Appearance, Habits, and Modes of Reproduction 16 



Tubuluria, its living Flowers and diffusion of the young Germs 1 7 



SertulariudcE, or those which resemble miniature Flowers .... 18 



Structure 18 



Food, Ova, Numbers, Luminositv 19 



