116 THE SENSE ORGANS AND REFLEX BEHAVIOUR 



visited in numbers the grey ring on the yellow background, but 

 the other grey cards received no visits. The conclusion seems to 

 be that where grey is surrounded by yellow, in the above manner, 

 it produces a physiological effect of blue in the eye of the bee. 

 The experiment also affords further evidence that mere brightness 

 of shade is not involved or the bees would have visited some or 

 other of the grey cards. 



The experiments of Hertz (1931-35) on the recognition of form 

 and pattern by bees are significant. It was shown that, as a 

 whole, bees tend to visit those patterns which show the largest 





Fig. 53. The amount of outline displayed in patterns a and h is 

 approximately the same, and bees can be trained to visit either. 

 Nevertheless, after short training bees showed a much higher 

 preference for a, while b becomes neglected when both patterns 

 are exposed simultaneously. The preference is for complex 

 patterns of many small units in variable directions, as compared 

 with regular patterns of few units and simple lines. (After 

 Hertz.) 



amoimt of contours or outlines within a given dimension. Hertz 

 distributed in various ways several black stripes of equal length 

 and breadth in areas of similar size. There resulted different 

 patterns with the same amount of contrast and of black and 

 white. The behaviour of the bees proved that patterns with the 

 most crossing-over and isolated units were much more attractive 

 than those which mainly showed regular parallel or concentric lines. 

 Thus in Fig. 53, for example, the pattern of crosses was visited in 

 preference to the concentric circles. In a similar way it was 

 found that bees could be conditioned to visit either patterns Pi 5 

 and F12, or G5 and P20 in Fig. 54, but not Pl5 and G5 or Fl2 



