6oO THE HISTORY OF BIOLOGY 



a different kind from the instinctive adaptation to normal conditions of life 

 which characterizes all animal life and which is based upon nervous reflexes 

 or simply upon tropisms induced by chemical and physical reactions, such 

 as are observed even in the most primitive of organisms. Such experiments 

 with individual experiences as their object are extremely difficult to carry 

 out, however, and still more difficult to interpret aright. On the one hand, 

 animals should be brought into situations which prove that they can learn 

 something new, but, on the other hand, they should not be faced with situa- 

 tions which involve violence to their true nature. The road to a true insight 

 into the subject is thus both long and difficult, and this explains to some 

 extent why so many contradictory statements and theories have arisen in 

 this sphere, even among observers who have been comparatively successful 

 in freeing themselves from preconceived opinions. The confusion has, of 

 course, been increased by so many students and dilettanti, for " Darwinistic " 

 purposes, ivanting necessarily to find in the animals as great and as human- 

 like an intelligence as possible. On the other hand, there have not been 

 wanting in modern times zoologists who have seen in animals nothing but 

 reflex mechanisms, and that, too, not merely as a result of their holding a 

 conservative view of life, but quite as often owing to ultra-radical views — 

 through endeavouring to restrict as far as possible the part played by the 

 psychic life in nature. We shall here cite in brief a few examples of different 

 views on these problems. 



Insect psychology 

 One subject that has specially interested animal-psychologists from ancient 

 times has been the psychology of the insects, particularly of the community- 

 forming Hymenoptera. Here in earlier times the imagination and credulity 

 have combined to celebrate veritable orgies of the fancy; one reads with un- 

 feigned amazement of all that people even in the latter half of last century' 

 imagined they could observe in the ant-communities. A much more sober 

 atmosphere has latterly prevailed, and it has now begun to be realized that 

 most of the actions of the ants must after all be due to inherited instinct. 

 A very prominent observer in this sphere is the Jesuit father Erich Wasmann 

 (born 1859), who has especially elucidated a number of facts in regard to 

 the ants' relations to many different kinds of parasites, which swarm in 

 the ant-heaps and which are often carefully looked after. Wasmann has 

 otherwise appeared as a keen opponent of Haeckelian monism and has elab- 

 orated in opposition to it a history of creation approved by Roman Catholic 

 authorities, in which Darwinism in most of its aspects has been ingeniously 



2 As an instance may be cited a story related by many authors — Romanes, for example 

 — of an American species of ant, according to which those ants whose duty it is to guard the 

 communities do so formed up in a regular square; within the square the workers carry out a 

 great manv equally intelligent and well-ordered movements. 



