application of his theory to the realm of instinct would 
not present it in the most favourable light. 
The argument which has hitherto been urged has been 
conducted with special reference to the reasoning of 
Mr. Darwin and Mr. Romanes. Mr. Darwin believed 
in the intelligence of the higher animals, and in the 
development of a simple into a more complex instinct 
by Natural Selection in spite of that intelligence. Mr. 
Romanes showed how in intelligent animals a new in 
stinct might be developed by the principle of “ lapsing ” 
intelligence, supplemented by Natural Selection ; and by 
the Natural Selection of non-intelligent action of a non- 
adaptive character, independently of the intelligence of 
the animal. I have endeavoured to show that these posi 
tions cannot be maintained in accordance with the facts 
of the case. If we had only animals to deal with, and 
if we believed that all animals were endowed with intel 
ligence, nothing more need to be said upon the subject 
of the development of instinct by means of Natural 
Selection. 
It may, however, be that the lowest animals are un 
intelligent ; are mere living automata, whose organisms 
respond to certain stimuli in consequence of acquired 
physical habits, which have in them no mental element 
whatever. And whether this is so or not, what are we 
to say with respect to the members of the vegetable 
world ? Shall we endow them with consciousness of in 
ternal change; with conscious sensitiveness to external 
conditions ; with intelligence which assists in adapting 
their organisms to external conditions ? Or shall we say 
that their organisms have acquired physical habits which 
have no mental element whatever? 
Now, it would seem that some writers believe that the 
element of intelligence is present in vegetable organisms.