118 THE SENSE ORGANS AND REFLEX BEHAVIOUR 



mentioned observer (Hertz, 1931) carried out further experiments, 

 using three-dimensional objects fashioned out of white paper and 

 placed on a white background. These different objects were 

 characterised only by their form and the distribution of shadows. 

 An overwhehning response was obtained, showing preference for 

 the more differentiated forms over the simple ones. Thus in 



Fig. 55. In this figure a, c, d are three-dimensional objects and b is a 

 Hat object ; all are made of the same material as the background 

 (white paper). Bees can be trained to visit any of these objects 

 when exposed singly. When they are exposed simultaneously 

 high preference is shown for the object with the most complex 

 form (a) which is due to the large amount of contrasting outline 

 and shadows. (After Hertz.) 



Fig. 55 that simulating a flower {a) was preferred to the plain 

 flat object (b). It was further noted that the pattern of the 

 shadows exercises an important influence. The more complicated 

 the shadows of an object are the more attractive the object 

 becomes : also, the deeper and darker the shadows on the objects 

 the more attractive they are. Certain experiments were carried 

 out by von Buddenbrock (1935) by using other insects such as 



