2 NATURE AND RELATIONS OF AN ORGANISM 



a sounding iron. Each metal would give its sound of character- 

 istic quality and the bars of different length of the same metal 

 would give a different note. 



2. Arrangement of the Components of Protoplasm. The ele- 

 ments which enter into living matter are built up into a number 

 of groups of compounds of which the proteids are the more im- 

 portant. Associated with these are a number of others such as 

 carbohydrates, acids, and mineral salts, which may or may not 

 actually enter into the composition of the protoplast. On the 

 basis of a crude physical classification these substances may be 

 roughly divided into diffusible crystalloids and non-diffusible 

 colloids. Starting from such classification protoplasm may be 

 considered as a mass of soluble and insoluble colloids saturated by 

 crystalloids in solution, some of which are disintegrating agents, 

 acting upon both colloids and crystalloids, the products of decom- 

 position and decomposable substances of both groups, and also 

 various compounds in process of rearrangement by the synthetic 

 activity of colloidal portions, by means of energy transformed 

 from chemical and radiant sources (See chemical and physiological 

 properties of the cell). 



The interactions of a mass of living matter of this general 

 structure give rise to several series of transformations or manifes- 

 tations, constituting the functions of which growth, absorption, 

 secretion, fermentation, nutrition, respiration, and movement are 

 the principal types. Stated in another form, the protoplast is com- 

 posed of several more or less simple machines each with its own 

 characteristic activity or motion. These machines are not inde- 

 pendent, but interlock as if a cog or wheel in one also formed a 

 portion of a second or third mechanism, which in turn has other 

 interlocking devices. The nature of such interrelations is ex- 

 tremely various. Thus certain of the machines stand side by side 

 and interlock at one point only forming a series, which may en- 

 gage with a second series at one, or every possible point of con- 

 tact. Any modification of the activity of one of these machines 

 is necessarily communicated to all of the others interlocked with 



