MODERN BIOLOGY 6oi 



introduced, though at the same time the old doctrine of creation has been 

 retained. In regard to the psychic life of the animals, its intrinsic resemblance 

 to human life is, of course, denied, and accordingly the reflexive and in- 

 stinctive functions are sharply emphasized and the idea of individual con- 

 sciousness rejected. Nevertheless, even the insects are allowed a certain power 

 of methodical action. Albrecht Bethe comes to a far more radical conclu- 

 sion, based on entirely opposite grounds; by means of extensive and in part 

 highly ingenious experiments he endeavours to prove, and in many cases 

 actually succeeds in doing so, that the actions of the ants are pure reflex- 

 actions. On the other hand, the famous student of psychiatry and psychology 

 AuGusTE FoREL, of Geneva, holds another view; after a series of careful ex- 

 periments he believes that he has been able to prove that insects can actually 

 learn by experience and thus possess intelligence. Another distinguished ob- 

 server of insect life who arrived at partially similar results was the well- 

 known English naturalist, banker, and philanthropist John Lubbock, 

 Lord Avebury (1834-1913). A very important animal psychologist was 

 George John Romanes (1848-94}, professor at Oxford, an enthusiastic sup- 

 porter of Darwin, whose theory he defended in a number of writings, in 

 which he especially attacked Weismann for his denial of the heredity of 

 acquired characters. In particular, he carried out experimental investigations 

 into the psychic life of the higher animals, which he believed to be — in 

 kind, if not also in degree — similar to that of human beings. Like Darwin, 

 however, he has accepted without criticism stories and anecdotes derived 

 from foreign sources, but his own observations are very keen. Animal psy- 

 chology has been dealt with experimentally with special keenness in Amer- 

 ica; among its pioneers in that country may be mentioned R. M. Yerks, 

 who has carried out a long series of experiments in order to try to discover 

 the power of animals to learn by experience; he is especially well known for 

 his "labyrinth," in which he placed animals, who then had to find their 

 way out as best they could. 



As a general result of the work of these investigators it may be men- 

 tioned that the vertebrate animals, at least the higher, can certainly acquire 

 knowledge from experience; whether the higher invertebrates can also do 

 so would seem to be more doubtful. But even experience can be exhibited 

 in different ways; either the animal finds its way in every fresh case to a new 

 experience, independent of what it has gone through before, or else it really 

 possesses the power to retain its experiences in the memory and to profit 

 by them in new situations. The former power is, of course, the more primi- 

 tive, as it is also the more usual in the animal kingdom; the latter, the ra- 

 tional power of adaptation, has certainly been observed to exist only in a 

 few of the very highly developed animals. Still more debatable are the cases 

 in which the power of grasping relations of number and other abstract ideas 



