CHAPTER n. 



DIFFERENCES BETWEEN ANIMALS AND PLANTS. 



Having row arrived at some definite notion as to live essen- 

 tial characters of living beings in general, we have next to 

 consider what are the characteristics of the two great divi- 

 sions of animated nature. What are the characters which 

 induce us to place any given organism in either the animal 

 or vegetable kingdom ? What, in short, are the differences 

 between animals and plants ? 



It is generally admitted that all bodies which exhibit vital 

 phenomena are capable of being referred to one of the two 

 great kingdoms of organic nature. At the same time it is 

 often extremely difficult in individual cases to come to any 

 decision as to the kingdom to which a given organism should 

 be referred, and in many cases the determination is purely 

 arbitrary. So strongly, in fact, has this difficulty been felt, 

 that some observers have established an intermediate king- 

 dom, a sort of no-man's-land, for the reception of those 

 debatable organisms which cannot be definitely and posi- 

 tively classed either amongst vegetables or amongst animals. 

 Thus, Dr Ernst Haeckel has proposed to form an intermediate 

 kingdom, which he calls the Regniim Protisticum^ for the 

 reception of all doubtful organisms. Even such a cautious 

 observer as Dr Rolleston, whilst questioning the propriety 

 of this step, is forced to conclude that " there are organisms 



