CONTENTS. 



SECTION I. 



NATUEAL HISTORY OF PAEASITES IN GENEEAL. 



CHAPTER I. 

 NATURE AND ORGANIZATION OF PARASITES. 



PAGE 



Definition — General scope of the Subject — Pseudoparasites — Degrees and 

 Varieties of Parasitism — Form of the Body — Organs of Fixation and 

 Locomotion — Commensalism, . . . . . . 1-: 



CHAPTER II. 



OCCTJERENCE OF PARASITES. 



Abundance — Distribution — Respiration and Respiratory Organs — Ectoparasites 



and Entoparasites — Nutrition and Mouth-Organs — Encystatiou, . . 10-21 



CHAPTER III. 



THEORY OF THE ORIGIN OF PARASITES REGARDED 

 HISTORICALLY. 



Theory of Spontaneous Generation — Heterogeny — Linnt and Pallas — Hypothesis 

 of Inheritance — The School of Rudolphi — First Proof of Metamorphosis in 

 Trematodes and Ceroaria — Eschricht and Steenstrup — Discoveries of 

 Dujardin, von Siebold, and van Beneden — Introduction of Helminthological 

 Experiment by Ktlchenmeister— Its further development, . . 22-41 



CHAPTER IV. 

 LIFE -HISTORY OF PARASITES. 



Sexual Maturity — Eggs and Embryos— Developmental Stage of Eggs when laid 

 — Migration of the Eggs — Worm-Nests— Continuous development and 

 Reproduction (RImbditis) — Haematozoa — Development of the Eggs 

 externally — Influence of Moisture — Constitution of the Egg-Shell — 

 Influence of Temperature — Duration of development, . . . 42-57 



Migration of the Young Brood— Eggs with contained Embryos— Escape of the 

 Embryos after digest^9j^f/^(f!^jj-y\l^g3^§§yf®the Host— Free Embryos 



