part I. 



GENERAL ZOOLOGY. 



CHAPTER I. 



LIVING MATTER. 



RETURNING to the animal kingdom, we find that 

 there runs throughout it a presence of the primary 

 basis of Hfe called protoplas}n. The living part of all 

 organisms (animals and plants) consists of this substance. 

 So far as we know, protoplasm cannot, at least under 

 present conditions of the earth's surface, arise spon- 

 taneously from less highly organised materials, although 

 it is one of the primary properties of protoplasm that it 

 can add to its bulk ox grow by the aggregation to itself of 

 non-living materials.^ 



According to present views, the whole animal world 

 owes its origin to growth of some primeval protoplasm, and 

 the constituent organisms owe their being to the fact that 

 this growth is discontinuous. 



The moving, thinking organism which we call a man 

 differs only in degree and not in kind from the isolated 

 and undifferentiated mass of protoplasm known as Amoeba. 

 Hence it is of primary importance that we should get a 

 clear idea of the physical, chemical and physiological pro- 

 perties of this basis of life, living protoplasm. 



* This statement does not preclude the possibility of living matter 

 having been in the past evolved from non-living matter ; but of this tve 

 know absolutely nothing. 



