266 N. E. McINDOO 



Structure 318 



External structure 318 



Internal structure 320 



Summary 332 



Physiology of olfactory pores 333 



Wings cut off 333 



Wings pulled off 334 



Bases of wings glued • 335 



Pores on legs covered '. 336 



Wings pulled off and pores on legs covered 337 



Stings extracted 339 



Summary 339 



General summary and discussion 341 



Literature cited 345 



INTRODUCTION 



Most students of bee behavior have considered this the fun- 

 damental factor in bee culture and have neglected the mechan- 

 isms through which behavior is manifest. Behavior consists 

 only of the reactions or responses brought about through the 

 senses and by means of internal stimuli. It is well to emphasize 

 the necessity of studying the structure and function of sense 

 organs and to form definite opinions concerning behavior only 

 after the morphology of these organs is thoroughly understood. 

 Behavior and the structure of the sense organs are inseparable 

 and should be studied at the same time. 



In the investigation here recorded two objects have been kept in 

 view: (1) To determine the relative sensitiveness of the honey 

 bee to different odors, so that it may be expressed numerically 

 for comparison under different conditions; and (2) to locate the 

 olfactory organs. The study of the behavior of normal bees under 

 experimental conditions is used as a basis for correctly interpret- 

 ing the observations on bees made abnormal for the purpose of 

 obtaining data which concern the two objects in view. Since 

 smell is probably the most important sense inside the hive and 

 is perhaps only of secondary importance outside, we should know 

 all that is possible concerning it. 



Some writers assert that bees have an acute sense of smell, 

 while others regard this sense in the bee as not important. Every 

 bee keeper believes that this sense plays an important part in 



