The Nervous System and the Senses 165 



and metathoracic segments (with the corresponding two 

 pairs of legs and wings) and the first abdominal segment, 

 which is fused with the thorax in the bee, as well as the first 

 segment of the abdomen behind the constriction. It should 

 be noted that nerves (W2Nv and WSNv) run to the bases of 

 the wings to innervate sense organs (p. 170). 



In the abdomen are five ganglia (8-7Gng) which send nerve 

 branches to the remaining abdominal segments. The third 

 and fourth ganglia lie one segment in front of the segments 

 which they innervate while the remaining ones are in their 

 own segments, the last (7Gng) supplying the remaining 

 posterior segments of the abdomen, it therefore being ac- 

 tually a fusion of four ganglia. 



The action of the nervous elements remains a matter 

 chiefly of conjecture. These cells have lost their contractility 

 and probably never regenerate nor divide in the adult bee. 

 Their function is obviously important, for if this system is 

 injured the coordination of the body is destroyed. However, 

 the cutting of the nerve cord does not cause death and even 

 if the thorax and abdomen are entirely separated the parts 

 may function independently. If the head is removed, the 

 animal can still walk and if the abdomen is removed it can 

 still take in food. These facts indicate that the nervous 

 control of the body is not centralized in the brain as com- 

 pletely as in man and in many other animals. Proper 

 correlation of movement cannot, however, take place unless 

 the nervous connections are intact. 



SENSE ORGANS 



So little is known of the structure and function of the sense 

 organs of bees that this subject must be discussed with 

 caution. We know that the simple and compound eyes 

 are the organs of sight and recently it has been found where 

 the organs of smell are located. Beyond this is a vast field 

 for investigation and a fertile field for speculation. 



