CHAPTER I 

 LIVING AND LIFELESS MATTER 



THE biological sciences all agree in their fundamental 

 subject matter, i.e., they all deal with things that are, or 

 have been, alive. In this one fundamental fact they differ 

 from the physical sciences. The boundaries between the 

 biological and the physical sciences are very indefinite 

 however, and investigations into the nature of life, or indeed 

 of any of its manifestations, would be of a very superficial 

 type were not the physical sciences involved. Biological 

 and physiological chemistry, as branches of the science 

 of physiology, are really branches of chemistry, but their 

 subject matter is material that has been living, or has been 

 derived from living things. 



What then is living matter as distinguished from non- 

 living matter? 



All animals and all plants are made up of a fundamental 

 living substance, together with derivatives from this sub- 

 stance, to which the name Protoplasm was given by Pur- 

 kinje in 1840. The term protoplasm cannot be accurately 

 defined because it represents a conception rather than a 

 definite thing, there being almost as many protoplasms as 

 there are animals and plants. The term should be used 

 much as we use the terms animal and plant, which refer to 

 no special animal or plant, and it cannot be described any 

 more accurately than can these concepts. Huxley has 

 called it the " Physical Basis of Life," and the physiologist 

 duBois Reymond described it as the " Agent of Vital 

 Manifestations." It is obvious that neither of these defini- 

 tions would enable us to recognize living substance. The 

 nearest approach to a description of protoplasm is to 

 describe the properties which protoplasm has in common. 



The most essential characteristic of this group of similar 



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