618 EVOLUTION OF ANIMALS Part V 



some of the results obtained by a famous student of animal behavior, Karl 

 von Frisch, through years of experiment and observation. His book, Bees, 

 Their Vision, Chemical Senses and Language, is largely made up of lectures 

 given in American universities during 1949 with motion pictures of the dances 

 of the bees. His conclusions have been termed "of basic importance to bio- 

 logical science and truly revolutionary in the special field of animal behavior" 

 (Donald R. Griffin). 



The Materials. In the course of the experiments, worker honeybees were 

 marked with colored symbols by which each one of a large number could be 



Trocheol 



Fig. 30.24. The respiratory system of the 

 worker honeybee with the air sacs that hold an 

 emergency supply of air. (Courtesy, Hunter 

 and Hunter: College Zoology. Philadelphia, 

 W. B. Saunders Co., 1949.) 



Spiracle 



identified. They were observed on combs among other bees in observation 

 hives, and at feeding stations where dishes of sugar water and control dishes 

 were placed on colored cards, and on flowers. The observation hives were in 

 diffused light and in red light (black to the bees). Experiments and observa- 

 tions were repeated, and often varied many times. They have also been re- 

 peated by others. 



Are Bees Color Blind? Bees can distinguish yellow, bluegreen, blue, and 

 ultraviolet (Fig. 30.25). Red and black are the same to bees for they are red- 

 blind. They and various other insects can distinguish certain red flowers, such 

 as scarlet poppies because these flowers reflect ultraviolet light. Ultraviolet 

 appears to be a distinct color for the bees (von Frisch). Color vision of man 

 and the bee is different; the human eye responds to more colors but not to 

 ultraviolet. 



Can Bees Recognize Different Shapes? They can distinguish solid ob- 

 jects from open ones, e.g., a solid triangle from three parallel lines (Fig. 



