THE ORIGIN OF AERVES. 277 



impulse was transmitted in the snail to the nearest nerve- 

 centre (B) in the animal's head, and thence " reflected " to 

 the muscles (F) of the body as a " motor " impulse, with 

 the result of the animal's withdrawal into private life for 

 a longer or shorter period. No matter where or how we 

 glance at the acts of living beings, the same actions are 

 to be witnessed. The presence of "consciousness" in 

 higher animals or its absence in lower forms, does not in 

 the least affect the community of method whereby each and 

 all act in response to the stimuli of the outer world. 



Entering the domain of the botanist, we may find feeling 

 and sensation not merely to be represented in the plant 

 world, but, in some cases, to approach very nearly indeed, 

 if not to actually eclipse in definiteness, the acts of many 

 animals. When a sensitive-plant (see Fig. 43) droops its leaf- 

 stalks and huddles its leaflets together, on being touched, in 

 what respect, it may be asked, do its actions differ from those 

 of many lower animals, such as sea-anemones and the like, 

 which evince, in their daily life, acts but little elevated 

 above the quiet vegetative existence of the plant ? Or when 

 the Venus's-flytrap (see Fig. 44) closes its treacherous leaf 

 on an insect which has touched one of its six sensitive hairs, 

 wherein shall it be said that the act of the plant differs from 

 that of the sea-anemone which seizes, by aid of its tentacles, 

 the unwary crab which has tumbled into a living pitfall in 

 its meanderings ? To these queries comparative physiology 

 can return no reply, save one, which admits that the actions 

 of plant and animal are alike "reflex " in nature ; and which 

 affirms that, despite the absence of demonstrable nerves in 

 plants and lowest animals for both are nerveless the acts 

 of the lower forms of life are bound up in a strange sequence 

 with those which regulate the existence of humanity itself. 



Primarily, then, it may be asserted that there is a striking 

 community and sameness of detail in the common nervous 

 acts of animals and plants. For between the essential 

 nature of the irritability witnessed in the two groups of living 

 beings there can be no just distinction drawn ; and the con- 



