nii TABLE OF CONTENTS. 



PAQB 



Purkinje. Von Mohl. Cohn. Schiiltze. Appearance and structure 

 of protoplasm, A typical cell. Its parts. 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 

 iabor. Protoplasm at work. Muscular contractions. Amo&ba on its 

 travels. "Rotation" in Nitella and AnacJtaris. "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 

 A animals similar but not identical c 20 



CHAPTER IV. 

 THE BIOLOGY OF AN ANIMAL: THE COMMON EARTHWORM. 



4. representative animal. Earthworms taken as a type. Their wide dis- 

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

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

 differentiation: antero-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. 



THE 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 » . » 72 



CHAPTER VL 



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 



