54 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 63 



used. (2) But when the antennae of Hymenoptera are mutilated in 

 the sHghtest degree, the insects are abnormal, and the reaction times 

 are slower than when unmutilated individuals are used, although it is 

 quite possible that the slower reaction times are caused by the 

 abnormal behavior of the insects rather than due to the theory that 

 some of the olfactory organs are prevented from functioning. {3) 

 When the maxillae of spiders are pulled off, no abnormal behavior 

 results, but the reverse is true for the honey bee. In both cases the 

 reaction time is slightly slow^er. (4) When the mouth parts of 

 honey bees are mutilated, the insects are abnormal and the reaction 

 times are slightly increased, which may be due to the alMiormality of 

 the insects, or to the view that the pores on these appendages are 

 prevented from functioning, or to both of these conditions combined. 

 (5) When the wings are pulled off artificially, most of the pores on 

 these appendages are lost and the reaction times are considerably 

 increased. (6) When the pores on the wings are covered with glue 

 the reaction times are much increased. (7) When most of the pores 

 on the legs are covered with vaseline, the reaction times are greatly 

 increased. (8) When either spiders or Hymenoptera are so muti- 

 lated that most of the olfactory pores are prevented from function 

 ing, the reaction times are increased many times, and the mutilated 

 individuals used are absolutely normal in all respects other than their 

 aljility to smell. 



DISCUSSION 



The following criticisms concerning" the physiological experiments 

 performed with the antenuce of various insects may be offered. Most 

 of the previous observers have studied the behavior of the insects 

 investigated in captivity for only a short time, while the remainder 

 have paid no attention at all to the behavior of their unmutilated 

 insects. They cut off either a few joints of both antennze, or these 

 entire appendages, or varnished them with paraffin, rubber, etc. 

 When a few joints are severed the sense of smell is apparently weak- 

 ened. This is true for bees also as ascertained by the author. \A'hen 

 both antennae are amputated or varnished the insects, as a rule, fail 

 to respond to substances which normally affect the olfactory sense. 

 They generally fail to respond to odors held near them and fail to 

 find food in captivity, and do not return to putrid meat and dead 

 bodies when removed from such food. Males so mutilated do not, 

 as a rule, seek females and show no responses when females are 

 placed near them. Such experiments w^ere seriously criticised until 

 Hauser in 1880 presented his apparently conclusive results. Many 



