34 THE ANATOMY OF THE HONEY BEE. 



touch, or smell makes also some sort of an impression on the insect 

 and varies in degree and kind much as it does in us, we may go on to 

 a study of the senses located on the antennae. 



Here, again, however, we are confronted by a difficulty, for while, 

 at first thought, it seems very easy to hold some strong-smelling sub- 

 stance near the antennae of a beetle, ant, or bee and observe the evident 

 displeasure with which the creature turns away, yet we may be en- 

 tirely wrong if we conclude that the insect " smells " the substance 

 that repels it. Strong-smelling, volatile liquids may simply produce 

 pain in some of the delicate nerve endings of the antennae. Some 

 other kind of a being, experimenting on our senses, might close up 

 pur nose and mouth and prove that we smell by means of our eyes 

 on observing the blinking we should perform when strong formalin 

 or ammonia was held close to the face. Furthermore, irritant gases 

 and volatile liquids affect the mucous membranes of our noses and 

 throats in a way quite indejDendent from the odor that we perceive, 

 and there is no reason why the same, may not be true of insects. As 

 pointed out by Forel, experiments on the sense of smell should be 

 made with odorous substances that the insect meets with in a state of 

 nature, which would be princijjally the materials it feeds on. In- 

 sects are indifferent to almost every mildly odorous substance not 

 used as food, which, however, does not prove that they do not sniell 

 them. 



Again, in many cases, it would be difficult to decide whether the re- 

 sults of an experiment should be accredited to smell or sight. For 

 example, every bee keeper knows that hungry bees are attracted to 

 honey a long distance from their hives, and it would seem almost self- 

 evident that they are guided by a sense of smell. Yet one might con- 

 tend that they find the honey by sight, as, indeed, is claimed by a 

 number of entomologists Avho have made experiments on the olfactory 

 powers of bees. This question has been decided in some other insects 

 by painting the eyes with some opaque substance or by removing the 

 antennae, but the evidence is not conclusive on either side in the case of 

 bees. 



Experiments made by a large number of competent investigators, 

 including Lubbock, Schiemenz, and Forel, have proved conclusively 

 that the organs of the sense of smell in insects are located principally 

 on the antennae. The most interesting of these experiments are per- 

 haps those which Forel ( 1903 ) made on carrion-feeding beetles. He 

 found the dead and putrid bodies of a hedgehog and a rat infested by 

 a swarm of these beetles belonging to several genera. He collected 

 more than 40 specimens from the carcasses and removed their an- 

 tennae. Then he placed them all at one place in the grass and moved 

 the dead bodies to a distance of 28 paces from the beetles where he 

 concealed them in a tangle of weeds. Examination the next day 



