224 THE PRINCIPLES OF HEREDITY 



379. The dragon-fly furnishes another example : 



" To-day I saw the dragon-fly 

 Come from the wells where he did lie. 

 An inner impulse rent the veil 

 Of his old husk. From head to tail 

 Came out clear plates of sapphire mail. 

 He dried his wings ; like gauze they grew. 

 O'er crofts and pastures, wet with dew 

 A living flash of light he flew." 



380. The dragon-fly begins his conscious life in the water. 

 Emerged from the egg, he knows his food and where to seek 

 it ; his enemies and how to shelter from them. At the fit 

 time, prompted by his instinct, he leaves the water and 

 climbs into an entirely new world. As a perfect insect he 

 rests till his wings are fit for use and then launches himself 

 into the air. Again he knows his prey and his enemies. 

 He knows his mate and how to deal with her, and she knows 

 the fit time and place wherein to lay her eggs. From first 

 to last he furnishes no evidence of memory. Like Sitaris he 

 seems to live the narrow round of his life unaided by ex- 

 perience. Both Sitaris and the dragon-fly have exactly the 

 same instincts as their predecessors, from whom as we see 

 they can have had no opportunities of learning. Instinct, 

 therefore, like all inborn characters, is transmissible from 

 parent to child. 



381. In man several very highly important instincts sur- 

 vive ; for example, the sexual and parental instincts, the 

 instinctive recognition of and delight in food, the sporting 

 instinct, the impulse to rest when tired, and the periodic 

 impulse to sleep. He is a very abnormal man in whom the 

 sight of a beautiful woman arouses no emotions. She is a 

 very abnormal woman who has no love for her child. Most 

 of us are capable of recognizing and enjoying food when it is 

 placed in our mouths. 1 Almost every child delights in play. 



blades, I suddenly cut off the tip. Of course the animal immediately 

 drew back into the shell, and remained there for a considerable time. 

 When he came out again I repeated the operation as before, and so on 

 for a great number of times, till all the tentacles had been progressively 

 cut away little by little. Yet the animal never learnt to associate the 

 scissors with the effect which always followed it, and so never drew in 

 until the snip had been given." (Mental Evolution in Animals, pp. 

 122-6.) Here memory of former sensations and events gave no help 

 to the crab ; but sensation alone was useful, for it caused him to with- 

 draw instinctively into his shelter. 



1 Practically speaking innutritious substances are generally dis- 

 agreeable. We are apt to take them only when they are combined with 

 and concealed by food. 



