xii CONTENTS. 



rAGE 



or LarvEe— Entrance of Free-living Larvae (Active Migration)— Passive 

 Migration (with Tood)— Viability of the Germs, .... 57-66 



Development of the Germs after Migration— Direct development— Wandering 

 within the Body of the Host — Development of the Larval or intermediate 

 stage ("Helminths of the Second Developmental Stage") — Sexually 

 mature Larvaa, .....•■■ 66-/0 



Change of Host — Development and Migration of the Distomes — Wandering of 

 Strongylus—Oi Bladder- Worms — Action of the Digestive Juices — Migration 

 of Pentastomum — Parasites with Pree Sexual Forms — Intermediate and 

 Definitive Hosts — Law of numerous Embryos, and its significance in 

 regard to Parasitism — Theory of erratic Embryos and of Degeneration — 

 Conditions of development — Duration of Life — Death, . . . 71-88 



CHAPTER V. 

 THE ORIGIN OF PARASITES, 



AND THE GRADUAL DEVELOPMENT OF PAEASITIC LIFE. 



Various kinds of Parasitism — Relations to Free-living Animals — Free-living 

 Nematodes — Rhabdonema nigrovenosum — Parasitic Nematodes with 

 Ehabditiform Larvae — Loss of the Ehabditic Stage — Cestodes and 

 Trematodes — Relations to the Hirudinea and Turbellaria — Acanthocephali 

 and Nematodes — Origin of the intermediate Host — Of the intermediate 

 stage, . . . . . . • . . . 89-119 



CHAPTER VI. 

 THE EFFECTS OF PARASITES ON THEIR HOSTS, 



PARASITIC DISEASES. 



History of the Subject — Nature of Parasitic Diseases— Loss of Nutritive 

 Material — Consequences of growth and of increase in numbers — Influence of 

 Wandering and Migration — Diagnosis of Helminthiasis — Therapeutics and 

 Prophylaxis — Etiology — Statistics of Human Parasites — Sources of Human 

 Parasites — Their occurrence and distribution, .... 120-170 



SECTION II. 



SYSTEMATIC ACCOUIs^T OF THE PARASITES 

 INFESTING MAN. 



INTRODUCTION. 



Number of Human Parasites — Larval and Adult Parasites — Entozoa and Epi- 



zoa — Zoological position, ....... 173-174 



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