CONSCIOUSNESS. 181 



associated with the idea that all organisms (as dis- 

 tinguished from inorganic substances) have souls : 

 the three ideas — life, soul, and consciousness — are 

 then taken to be co-extensive. Another modification 

 of this view holds that, though these fundamental 

 phenomena of organic life are inseparably connected, 

 yet consciousness is only a part of the activity of the 

 soul, and of the vital activity. Fechner, in particular, 

 has endeavoured to prove that the plant has a " soul," 

 in the same sense as an animal is said to have one ; 

 and many credit the vegetal soul with a consciousness 

 similar to that of the animal soul. In truth, the 

 remarkable stimulated movements of the leaves of the 

 sensitive plants (the mimosa, drosera, and dionaea), 

 the automatic movements of other plants (the clover 

 and wood-sorrel, and especially the hedysarum), the 

 movements of the " sleeping plants " (particularly 

 the papiUonacea), etc., are strikingly similar to the 

 movements of the lower animal forms : whoever 

 ascribes consciousness to the latter cannot refuse it 

 to such vegetal forms. 



V. Cellular theory of consciousness. — It is a vital 

 property of every cell. The application of the cellular 

 theory to every branch of biology involved its exten- 

 sion to psychology. Just as we take the living cell to 

 be the " elementary organism " in anatomy and physi- 

 ology, and derive the whole system of the multicellular 

 animal or plant from it, so, with equal right, we may 

 consider the " cell- soul " to be the psychological unit, 

 and the complex psychic activity of the higher organ- 

 ism to be the result of the combination of the psychic 

 activity of the cells which compose it. I gave the 

 outlines of this cellular psychology in my General 

 Morphology in 1866, and entered more fully into the 



