THE OLFACTORY SENSE OF COLEOPTERA. 447 



for some time after being caught, and some feign death. As a 

 rule the longer they are confined and the more they are handled, 

 the more satisfactory they are to experiment with. Five species 

 without antennae responded to odors as promptly as did the same 

 species unmutilated. Two species without antennae responded 

 to odors more slowly than did the same species unmutilated. 

 Since these were abnormal in behavior and judging from the 

 reaction times of the other nine species with antennae pulled off, 

 it is only reasonably to attribute the slow reaction times of these 

 two species to their abnormal condition caused by the antennae 

 being pulled off. The six species so mutilated that most of their 

 olfactory pores on the elytra and wings were prevented from 

 functioning responded from two to five times more slowly than 

 did the same species unmutilated or with the antennae pulled 

 off. The two species so mutilated that most of their olfactory 

 pores on the elytra, wings and legs were prevented from func- 

 tioning responded from two to six times more slowly than did 

 the same species unmutilated or with the antennae pulled off. 



From all the preceding results, it seems that the antennae do 

 not carry any of the olfactory organs, while the olfactory pores 

 found on the peduncles of the elytra, on the dorsal surfaces of 

 the wings, on the trochanters, tibiae, sometimes on the femurs 

 and tarsi, and perhaps on the mouth appendages, are the true 

 olfactory organs in beetles. 



SUMMARY. 



In making a comparative study of the olfactory pores in 

 beetles, 50 species belonging to 47 genera and representing 34 

 families were used. A group of pores is always present on the 

 peduncle of each elytron. It lies on the dorsal side of the well- 

 exposed radial plate. The number of pores on a pair of elytra 

 varies from 12 to 310. As a rule, the more pores in the group the 

 smaller they are and the closer they are together. 



Of the 47 winged species examined, ii have only one group of 

 pores on each wing, 21 have two groups on each wing, 12 have 

 three groups on each wing, and 3 have four groups on each wing. 

 These groups are always located on the dorsal surface. Only 

 occasionally are a few scattered pores found on the ventral side 



