2 HABIT AND INTELLIGENCE. [chap. 



formative unconscious intelligence that determines the formation of 

 gence!' i^s mouth and its eyes.^ The only reason why we think 

 there is anything exceptionally wonderful in such instincts 

 as those of the bee and the wasp, is that they are com- 

 Instinctis paratively uncommon. Instances of motor instincts, so 

 wonSl definitely adapted to a very special purpose, are found in 

 than ]but a few out of the vast number of animal species ; while 



intSL^^ every animal that has well-developed eyes presents an 

 S®'"^''- instance of the adaptation of means to purpose by un- 

 conscious formative intelligence, which is quite as definite 

 as that shown in any motor instinct, and far more delicate 

 and subtle. Considered in itself, and without reference to 

 its being exceptional or common, the bee's eye is at least 

 as wonderful as the bee's cell. 



These instincts of bees and wasps are the most remark- 

 able and the most extreme case of motor actions directed 

 by a definite, intelligent purpose, which purpose is yet 

 totally unconscious. But they are distinctly exceptional ; 

 so that, in order to understand the relations between the 

 different intelligent functions, we must take a different class 

 of instances, which show a direct, and not merely an in- 

 ferred connexion between formative and motor intelligence. 

 There is no more clear and definite instance of the 

 adaptation of means to purpose in the whole organic 

 Purpose in creation than in the structure of the iris, enabling it to 

 tion and^' Contract, involuntarily and spontaneously, in order to 

 action of protect the retina against too much light. The formation 

 the ins. ^^ ^^^ ^.^ ^^ ^ ^^gg ^^ unconscious formative intelligence, 



and its action in closing against the light is a case of 

 unconscious motor intelligence. The action of the iris, 

 though a motor action, is as purely unconscious as the 

 formative actions : it cannot be controlled by the will, it is 

 not accompanied by consciousness, nor does it always even 

 depend on sensation ; for there is a kind of blindness in 

 which the optic nerve does not transmit the sensation of 

 light to the brain, and yet the iris opens and closes as in a 

 healthy eye.^ From this there is a perfect gradation to 



1 See Note at end of chapter. 



2 Carpenter's Human Physiology, p. 533. 



