osited, and is
provided with fresh meat when the time comes.

"Now Dr. and Mrs. Peckham have shown that the sting of the wasp is NOT
UNERRING, as Fabre alleges, that the number of stings is NOT CONSTANT,
that sometimes the caterpillar is NOT PARALYZED, and sometimes it is
KILLED OUTRIGHT, and that THE DIFFERENT CIRCUMSTANCES DO NOT APPARENTLY
MAKE ANY DIFFERENCE TO THE LARVA, which is not injured by slight
movements of the caterpillar, nor by consuming food decomposed rather
than fresh caterpillar."

This illustrates how love of the marvellous may mislead even so careful
an observer as Fabre and so eminent a philosopher as Bergson.

In the same chapter of Dr. Drever's book there are some interesting
examples of the mistakes made by instinct. I will quote one as a sample:

"The larva of the Lomechusa beetle eats the young of the ants, in whose
nest it is reared. Nevertheless, the ants tend the Lomechusa larvae
with the same care they bestow on their own young. Not only so, but they
apparently discover that the methods of feeding, which suit their own
larvae, would prove fatal to the guests, and accordingly they change
their whole system of nursing" (loc. cit., p. 106).

Semon ("Die Mneme," pp. 207-9) gives a good illustration of an instinct
growing wiser through experience. He relates how hunters attract stags
by imitating the sounds of other members of their species, male or
female, but find that the older a stag becomes the more difficult it
is to deceive him, and the more accurate the imitation has to be. The
literature of instinct is vast, and illustrations might be multiplied
indefinitely. The main points as regards instinct, which need to be
emphasized as against the popular conceptions of it, are:

(1) That instinct requires no prevision of the biological end which it
serves;

(2) That instinct is only adapted to achieve this end in the usual
circumstances of the animal in question, and has no more precision than
is necessary for success AS A RULE;

(3) That processes initiated by instinct often come to be performed
better after experience;

(4) That instinct supplies the impulses to experimental movements which
are required for the process of learning;

(5) That instincts in their nascent stages are easily modifiable, and
capable of being attached to various sorts of objects.

All the above characteristics of instinct can be established by purely
external observation, except the fact that instinct do