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 bio- 

 logical 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- 

 kin je in 1840. The term protoplasm cannot be accurately 

 defined because it represents a conception rather than a defi- 

 nite 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 'Physi- 

 cal Basis of Life," and the physiologist duBois Reymond 

 described it as the " Agent of Vital Manifestations." It 

 is obvious that neither of these definitions would enable us 

 to recognize living substance. The nearest approach to a 

 description of protoplasm is to describe the properties which 



protoplasms have in common. 



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