TABLE OF CONTENTS, 



PAQE 



Purkinie. Von MohL Cohn. Schultze. Appearance and structure 

 ^protoplasm. A typical cell. Itsparts. Cytoplasm and the nucleus. 

 The origin of cells. Segmentation of the egg, differentiation of the 

 tissues the genesis of the " body," and the physiological division of 

 labor Protoplasm at work. Muscular contractions. Amoeba on i 

 travels. "Rotation" in Nitella and Anackaris. " Circulation "of 

 the protoplasm in hair-cells of spiderwort. Ciliary motion. The 

 sources of protoplasmic energy. Metabolism and its phases. Vital 

 energy does not imply a "vital force." The chemical relations of 

 protoplasm: proteids, carbohydrates, and fats. Physical Relations: 

 temperature, moisture, electricity, etc. The protoplasm of plants and 

 of animals similar but not identical 20 



CHAPTER IV. 



THE BIOLOGY OF AN ANIMAL: THE COMMON EARTHWORM. 



A representative animal. Earthworms taken ns a type. Their wide dis- 

 tribution. The common earthworm. Its name ; habitat ; habits ; 

 food; castings; influence on soils; burial of objects; senses. Its 

 differentiation: autero- posterior and dorso-ventral. Its symmetry: 

 bilateral and serial. Plan of the earthworm's body. Organs of the 

 body and the details of their arrangement in systems : alimentary ; 

 circulatory; excretory, respiratory; motor; nervous; sensitive; etc.. 41 



CHAPTER V. 



TEE BIOLOGY OF AN ANIMAL: THE COMMON EARTHWORM (Continued). 



Definition of reproduction. The germ-cells. Sexual and asexual repro- 

 duction. Regeneration. The reproductive system of the earthworm. 

 Its copulation and egg-laying. The process of fertilization, and the 

 segmentation or cleavage of the egg. The making of the body. The 

 gastrula. The three germ-layers : ectoblast, entoblast, mesoblast. 

 Brief statement of the phenomena of cell-division, and of nuclear 

 division or karyokinesis. The making of the organs. The fate of 

 the germ-layers. The germ-plasm . 73 



CHAPTER VI. 



THE BIOLOGY OF AN ANIMAL: THE COMMON EARTHWORM (Continued). 



The microscopic anatomy or histology of the earthworm. The funda- 

 mental animal tissues and their constituent cellular elements. Epi- 

 thelial, muscular, nervous, germinal, blood, and connective tissues, 

 and their distribution in the various organs. Microscopic structure 

 of the body-wall ; of the alimentary canal ; of the blood-vessels ; of 

 the dissepiments ; of the nervous system, ganglia ; etc. 90 



