Poulton. | 390 [May 16, 
Time will permit me to deal with only one class of characters, 
and that is associated with the nervous system and manifested as 
instinct. These instinctive actions are generally thought to be 
the strongest evidence in favor of Lamarckian evolution. It has 
been argued that we cannot explain the instinctive action of 
animals — the wonderful instincts which are due, as we know, to 
modifications of the nervous system, — except by supposing that 
animals have intelligently modified their actions in consequence 
of experience and observation, and that the result has then been 
transmitted and has become the non-intelligent instinct of their 
offspring. If we had no other explanation of instinctive action, 
such an interpretation would constitute a strong support to the 
Lamarckian theory. 
I do not, however, believe that this is the only, or, indeed, the 
correct explanation of instinct. In considering this question, we 
must distinguish between the instinct manifested by many of the 
higher invertebrate animals and much that we are apt to call the 
instinct of the vertebrates. A great many actions which are put 
down to instinct in the higher vertebrates, such as birds and 
mammals, are not instinctive at all, but merely the result of 
observation during the life of the individual. We see an example 
of this in the action of the seal which, as Nansen tells us, took up 
a position on the outer ice-floes to escape the dangers of the polar 
bear, and afterwards incurred this very danger on the inner floes 
to avoid the greater peril from the hunter. This is a clear case 
of reasoning from the results of observation, and no instinctive 
avoidance of danger. So also with a bird which flies away if you 
have a gun in your hand, but allows you to come near when you 
have a walking-stick. This is the result of reason and not merely 
instinct; and we must carefully distinguish between a lesson 
learned by the individual, however well learned and easily 
repeated it may be, and a true instinctive action which was never 
learned at all but sprang fully formed into existence. Such true 
instincts certainly occur in the higher vertebrates, such as the act 
of sucking performed so perfectly without any education or 
practice by the newly born mammal. In the lower animals such 
true instincts are relatively far more numerous and play a most 
prominent part in the life of the individual. In these cases of 
true instinct I would suggest that we are dealing with actions 
which have never been intelligent at any time in the past history 
