12 



FIELD ZOOLOGY. 



known to find a plate of honey left on the kitchen table. 

 A human being could hardly have smelled the honey at 

 close range. In the case of human beings, the olfactory 

 nerve of one person may carry stimuli for certain odors, 

 and not be at all responsive for other odors. Again, it is 

 difficult for a human being to discriminate between 



odors somewhat similar, as odors 

 of different flowers, different teas, 

 or different foods. Personal clean- 

 liness generally obliterates for us 

 any olfactory recognition mark of 

 our own race ; and yet the approach 

 of a member of a different race is 

 an instant olfactory suggestion. 



Out of all this must come this 

 concession : the fact that we do not 

 perceive an odor does not prove 

 that the olfactory sense of some 

 other living being may not respond 

 to it. . - 



The immediate smelling organs 

 in the case of insects are exceedingly 

 small papillae or pits, at the bottom 

 of which a fiber from the olfactory lobe of the brain 

 ganglion is spread under the thin body tegument. These 

 organs are often found on the antennae. Carrion beetles 

 have what seem to be unmistakably olfactory organs on 

 their antennae and also on their palpi. Flesh flies, which 

 are so often attracted considerable distances by the odor 

 of decaying meat, lose this means of finding their food 

 after their antennae are removed (Hauser). Many 

 moths use this sense as a means of recognition of the other 

 sex, and have been proved by experiment to be unable 



FIG. 4. Antenna of a 

 burying beetle, Necrophorus 

 Americanus, showing sense 

 pits in end segments. 



