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MNEMOTAXIS 



MNEMOTAXis is the most complicated method of orientation and 

 allows the animal to deal ivith all the elements of a coynplex situation in 

 the light of experience gained in the past (Kiihn, 1919-39). In the 

 previous reactions we have studied, the response is made to one 

 stimuhis only or the synthesis of several, and it may be either direct 

 as in tropotaxis or indirect as in menotaxis, a simple mechanism which 

 becomes effective by the inhibition of all stimuli but the dominant one. 

 These more primitive taxes determine the reactions of lower species, 

 and although they enter into the total response of the higher animals 

 and can be studied separately in experimental conditions, the normal 

 activities of the latter are rarely based on so simple a pattern of 

 behaviour. It is true that the homing honey-bee can orientate itself 

 with regard to the sun and that this is the only mechanism available to 

 the soaring bird as it rises in strange surroundings, but both also make 

 use of other clues in ordinary life as soon as they can appreciate objects 

 in a known environment. In this more elaborate type of orientation 

 two new capacities are added to one or other of the simpler methods — 

 (1) the ability to integrate a number of stimuli simultaneously instead 

 of inhibiting all but one, and (2) the modification of a direct automatic 

 response by the factor of memory through a process of conditioning. 

 By a synthesis of these factors the animal is thus able to deal with a 

 complex situation as a whole (Adlerz, 1903-9 ; v. Buttel-Reepen, 

 1907 ; Turner, 1908 ; Rabaud, 1924-26 ; Wolf, 1926-27 ; Hertz, 

 1929-31 ; Friedlander, 1931 ; Tinbergen, 1932-51 ; Tinbergen and 

 Kruyt, 1938 ; Baerends, 1941 ; and others). 



In its simplest form this is illustrated by the experimients of van Beusekom 

 (1948) with the homing digger wasp, Philanthus (Fig. 50). The initial training 

 situation to which the wasp was conditioned was a square block set at right 

 angles close to the nest and a model of a tree 1 metre from the nest. In the 

 test experiment the block was turned through 45" and the tree displaced first 

 to one side and tlien the other ; the wasp approached the corner opposite to that 



