88 
Philippine Journal of Science 
finding its way out of a very simple labyrinth with greater and 
greater accuracy as the number of trials is increased. Such a 
“mind” is probably possessed by the hermit crab, but it would 
require a great stretch of imagination to believe that the hermit 
crab, if it really feeds the anemone, does so with the knowledge 
that it is caring for an animal which protects it from enemies; 
or that, when the hermit crab removes the sea anemones from a 
shell which it has left and plants them on a new home, it knows 
that they will be of future use ; or that, when the anemone allows 
itself to be pinched and pulled and pried away from a shell by a 
hermit, it knows that it is in the hands of a friend. We cannot 
believe that this lowly crustacean, during its lifetime, has learned 
by experience that its care of the sea anemone is advantageous, 
although we know that crabs in general do profit by experience. 
Yet, assuming that the remarkable behavior of the hermit is due 
to instinct — that is, to an “inherited combination of reflexes” 
which have been so brought together by the nervous system that 
the behavior has become fixed and adaptive in the species — it is 
extremely difficult to conceive how it has acquired these habits. 
