HUMIDITY RESPONSES FROM ANTENNAE OF COCKROACH LEUCOPHAEA MADERAE

A change from drier to wetter air is stimulatory in the majority of cases while a shift to drier air is most apt to reduce or inhibit the response. In the smaller number of tests in which the response pattern was opposite to this, a few preparations showed only the opposite type while in most cases responses were evident only after the antenna had been exposed to wet air several times and some adaptation of the dominant response had taken place. The definite correspondence between increased and decreased activity for both directions of change would seem to indicate 2 types of receptor: a dominant one which fires more with the change from drier to wetter air and less with the reverse change and a less numerous one which responds in the same way to opposite shifts in humidity conditions.