GENERAL MORPHOLOGY AND PHYSIOLOGY. 



General Zoology: Animal Morphology. In vital phenomena 

 a certain degree of similarity can be followed through the animal kingdom; 

 the way in which animals are nourished and reproduce their kind, move, 

 and gain experience, is essentially the same in great groups. Correspond- 

 ing to this, the apparatus concerned with the above-mentioned functions, 

 the organs of nutrition and reproduction, 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 characters which always 

 or frequently recur. 



(Ecology or Biology. When by means of anatomy and embryology 

 we have learned the general character of the organism, we must then 

 study its relations to the environment. In this study of the conditions of 

 animal life, cecology or biology, we 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. The synthesis of an organism, of which we can only 

 gain an idea by general anatomy, actually takes place in nature during the 

 development of every animal. Embryologically every organism is at 

 some time a simple element, a cell; this divides and gives rise to tissues; 

 from the tissues are formed organs, and from the organs the regularly 

 membered whole of the animal body is composed. 



I. GENERAL ANATOMY. 



The Morphological Units. The expression 'constituent parts of the 

 animal body' can be used in a double sense. We can speak of the chemical 

 units, the chemical combinations, which form the tissues; these are the 

 subject of animal chemistry, and may therefore be passed over here. 

 But we may also speak of the units of form (morphological units) of the 

 animal body; these are the cells. These and their transformation into 

 tissues, organs, and entire animals are for us of vastly greater importance. 



50 



