THE DISPLAY OF ENERGY 377 



When reflexes follow one another in an orderly succession involving 

 a chain of reflexes, one step of which determines the next, they are 

 called native behavior 'patterns. That these are inherited patterns is 

 seen in such acts as cocoon-making, egg-laying, or mating behavior, 

 which only take place once in the life of the individual. 



There have been two lines of e\olution in behavior patterns, one 

 culminating in the insects, the other in nian. These two groups are 

 the most successful in the animal kingdom. The insect group 

 embraces probably over 625,000 species, while man is but a single 

 species. It is estimated that many insects, particularly the ants, 

 have undergone no significant structural changes since the Oligocene 

 period some thirty million years ago. They are at the summit of 

 their development while man is just beginning. Insects mark the 

 top notch of these native behavior patterns. Their innate stereo- 

 typed functions make them, in the words of one writer, "a bag of 

 tricks." Their actions depend upon a series of associations which 

 form a sequence or chain of events. These chain-reflexes in many 

 cases have formed so complicated a pattern that the ensuing actions 

 appear to be intelligent. However, when these actions are carefully 

 analyzed, by means of experiments, they exhibit a far different type 

 of response. The well-known example given by Fabre will suffice to 

 illustrate how such a chain of reflexes works. One of the Sphex wasps 

 habitually paralyzes a cricket by stinging it, and then drags it to its nest 

 as food for its larvae. After the female w^asp has dragged the paralyzed 

 victim to the entrance of the burrow, she leaves it there and goes inside, 

 apparently to inspect conditions. In his experiment, Fabre moved the 

 cricket a short distance from where it was left and when the wasp came 

 out, finding the cricket out of its original position, she seized it again and 

 dragged it back to the mouth of the nest, and again went in. Fabre re- 

 moved the cricket forty times, and for forty times the wasp repeated its 

 actions. As Huxley has so aptly said, all she knew was, "drag cricket 

 to the threshold — pop in — pop out —pull cricket in." In this case the 

 initial stimulus that started this whole chain of events was the maturing 

 of the egg in the body of the wasp, and the breaking of a single link in the 

 chain of associations was sufficient to break the sequence of events. Ex- 

 amples of these chain reflexes, which have been called instincts for v/ant 

 of a better term, are so numerous that volumes have bcnni written about 

 them. The many fascinating books of Fabre, the intriguing volume 

 on wasps by the Peckhams, the still interesting classic entitled, Ants, 

 Bees and Wasps, by Sir John Lubbock, are all worth reading. 



