ZOOLOGY AND BOTANY, MICROSCOPY, ETC. L39 



slightest degree, the behaviour is abnormal, and the reaction times are 

 slower than when intact individuals are used. It may be, however, that 

 the slowness is due to the abnormal behaviour of the insects and not to 

 the fact that some of the olfactory structures are kept from functioning. 



When the chelicerae of spiders are removed, no abnormal behaviour 

 is observed. The reverse is the case when the maxillae of bees are 

 removed. In both cases the reaction ti re is slightly slower. When 

 the mouth-parts of honey bees are mutilated the behaviour of the insects 

 is abnormal and the reaction times are slightly increased. This may be 

 due to the abnormal behaviour of the insects, or to the fact that the 

 pores on the mouth-parts are prevented from functioning, or to both 

 conditions combined. The removal of the wings increases the reaction 

 times. When the pores on the wings are covered with glue the reaction 

 times are much increased. When most of the pores on the legs are 

 covered with vaseline the reaction times are greatly increased. When 

 spiders or Hymenoptera are so injured that most of the olfactory pores 

 are prevented from functioning, the reaction times are greatly increased, 

 even when the behaviour is otherwise quite normal. 



When the antennae of any insect are injured the behaviour is no 

 longer normal, and the failure of the insect to respond to odours near 

 it does not prove that the seat of smell is in the antennae. It must be 

 noted that cutting the antennae exposes a large nerve and many sense 

 cells. The insect is no longer normal in its behaviour, and in some 

 cases the injury is rapidly fatal. 



The author considers the structure of the antennae in reference to 

 the widespread view that the sense of smell is located there. In the 

 honey bee the pore plates can scarcely be considered as olfactory organs, 

 for the drone has almost eight times as many as the queen, and yet 

 responds to the odours presented in slightly more than one half the time. 

 It is true that those of the queen are considerably larger, but even on 

 this basis the reaction times are not comparable. 



The pegs may be entirely eliminated as olfactory organs, for they 

 are absent in the drone, while they are abundant in the worker and the 

 queen. Drones, queens, and workers have about the same number of 

 Forel's flasks and pit pegs. Schenk's view that the pegs receive odour 

 stimuli in the queens and workers, while Forel's flasks and the pit pegs 

 function in this way in the drones is inconsistent, because if the last two 

 structures function for such a purpose in the drones, why should they 

 not do so in the females ? Since these two structures are few in number 

 and many times smaller than the pegs, we cannot compare them physio- 

 logically. 



The author's argument is that the distribution of these antennary 

 organs in the honey-bee does not correspond with the facts experiment- 

 ally established as to the reaction times of the queens, workers, and 

 drones when tried with the various odours. It is otherwise, however, 

 with what the author calls olfactory pores. If the reaction time of each 

 caste of bees is compared with the total number of olfactory pores, a 

 consistent inverse ratio is observed. A drone has 2600 pores and 

 responds in 2*9 seconds ; a worker has 2200 pores and responds in 3*4 

 seconds ; and a queen has 1800 pores and responds in 4*9 seconds. 



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