GENERAL MORPHOLOGY AND PHYSI- 

 OLOGY. 



General Zoology : Animal Morphology. In the vital 

 phenomena of animals a certain degree of similarity can be 

 followed through the entire animal kingdom ; the way in 

 which animals are nourished and reproduce their kind, how 

 they move, and how they gain experience, is in great 

 groups essentially the same, and even in case of widely 

 separated forms shows many agreements. Correspond- 

 ing to this, the apparatus which is concerned with the 

 above-mentioned functions, the organs of nutrition and re- 

 production, of motion and sensation in their grosser and 

 finer structure, and in their ontogeny, must be similar to 

 one another and show evidence of some fundamental char- 

 acters which always or frequently recur. All this needs a 

 general explanation before w r e can go into a description of 

 the separate branches of animals. This explanation is the 

 subject of General Zoology, specially of General Anatomy 

 and Embryology, or Animal Morphology. 



CEcology or Biology. If by means of anatomy and 

 embryology we have learned the general character of the 

 animal organism, we must yet farther study their relations 

 to their environment. For this study of the conditions of 

 animal life, CEcology or Biology, we have to consider the 

 geographical range of animals, their distribution over the 

 surface of the earth and in the different depths of the sea ; 

 further, the reciprocal relations of animals and plants, 

 and of beast to beast, as these find special expression in 

 colony-building, symbiosis, parasitism, etc. 



General Anatomy. In the case of General Anatomy, 

 with which we shall begin, the fundamental proposition 

 will be, How does an organism build itself up from its con- 

 stituent parts. We shall thereby in spirit follow the 



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