IN HIGHER INVERTEBRATES 53 



tance; but were there no profiting by experience most of the shots 

 would go wide. Parental care might be here symbolized by sup- 

 posing the raw beginner protected and instructed by an expert 

 shot until the necessary experience had been acquired. 



We do not know how far down in the scale of animal life some 

 sort of consciousness exists, but the dawn of intelligence is marked 

 by the appearance of what Lloyd Morgan calls " effective con- 

 sciousness ", i.e. a realization of existence which enables more or 

 less successful adjustments to a changing environment. 



In ourselves we find Intelligence reinforced by Reason, the 

 "ideational stage " in mental evolution, where actions depend upon 

 motive, instead of being due to mere impulse dictating certain 

 sorts of behaviour "on the spur of the moment". It involves 

 appreciation of abstract ideas with powers of reflection and deliber- 

 ation, leading us to trace the relations between cause and effect, 

 and to construct ideals of existence by which our conduct is more 

 or less regulated. The dim beginnings of Reason are probably 

 to be found among the higher animals, but the body of facts with 

 which we are at present acquainted is far too small to justify 

 positive statements or wide-sweeping generalizations. 



INSTINCT AND INTELLIGENCE IN HIGHER INVERTE- 

 BRATES (INVERTEBRATA) 



The most instructive cases so far investigated are to be found 

 among Insects (Insecta) and Molluscs (Mollusca), and it will be 

 enough for our present purpose to briefly describe a few of these. 



INSTINCT AND INTELLIGENCE IN INSECTS (INSECTA). A good 

 example of the stereotyped nature of complex instincts is given 

 by Fabre (in Souvenirs entomologiques} in his account of one of 

 the Mason- Bees (Chalicodoma muraria) native to South Europe. 

 The female makes a nest consisting of nine or ten cells placed one 

 on top of the other, using cement made of a mixture of earth and 

 saliva, to which little stones are added. After each cell is built 

 it is stored with honey and pollen, after which an egg is laid in it, 

 and a roof is added. The entire series is then thickly covered with 

 cement till the nest assumes a hemispherical form. The three 

 operations of building, storing, and egg-laying which take place 

 in regard to each cell follow one another with automatic regularity, 

 and there is no harking back to an earlier stage. For conditions 



