I.IVING PLANTS 



"What constitute 

 special senses 



Sense of 

 contact 



If we ask ourselves what could properly be 

 considered as constituting special senses in 

 plants, it will be necessary to remember that 

 in the broadest ecological import the special 

 senses of animals are the conspicuous ways 

 in which they respond to particular kinds of 

 external stimuli in promoting their well-being, 

 and that the same must be true of plants. 

 Knowing that irritability is a fundamental 

 property of all living matter, let us see w^hat 

 advantages the animal and the plant could 

 secure by its special development. 



It is unquestionable that the paramount 

 necessity of every organism is self-preserva- 

 tion. To secure food, to avoid injury, and to 

 obtain the requisite supply of light, heat, 

 moisture and air, may be considered the funda- 

 mental necessities of every living being, 

 whether man or monad, tree or microbe. It 

 is in these directions, therefore, that we must 

 look for special senses. 



The animal has developed a quick response 

 to contact. This is probably the most univer- 

 sal of all the senses, and in its lowest forms 

 is little removed from simple irritability. It 

 primarily contributes to the animal's safety, 

 as it gives warning of the proximity of uncon- 

 genial or dangerous objects, and is also an 

 important factor in the operation of securing 

 food, and in many minor operations. It is a 



