Riley Presidential Address. 



some of the abdominal joints have been carefully described. The 

 fact that so many insects have the power of producing sounds 

 that are even audible to us, is the best evidence that they possess 

 auditory organs. These are, however, never vocal, but are situ 

 ated upon various parts of the body or upon different members 

 thereof. 



SPECIAL SENSES AND SENSE-ORGANS. While from what has 

 preceded it is somewhat difficult to compare the more obvious 

 senses possessed by insects with our own. except, perhaps, the 

 sense of touch, it is, I repeat, just as obvious to the careful 

 student of insect life that they possess special senses which it is 

 difficult for us to comprehend. The sense of direction, for in 

 stance, is very marked in the social Hymenoptera which we have 

 been considerering, and in this respect insects remind us of many 

 of the lower vertebrates which have this sense much more strongly 

 developed than we have. Indeed, they manifest more especially 

 what has been referred to in man as a sixth sense, viz., a certain 

 intuition which is essentially psychical, and which undoubtedly 

 serves and acts to the advantage of the species as fully, perhaps, 

 as any of the other senses. Lubbock demonstrated that an ant 

 will recognize one of its own colony from among the individuals 

 of another colony of the same species, and when we consider that 

 the members of a colony number at times not thousands but 

 hundreds of thousands, this remarkable power will be fully ap 

 preciated. 



The neuter Termites are blind and can have no sense of light 

 in their internal or subterranean burrowings; yet they will 



undermine build 

 ings and pulverize 

 various parts o f 

 elaborate f u r n i- 

 ture without once 

 gnawing through 

 to the s u r f a c e, 

 and those species 

 which use clay 

 will fill up their 

 burrowings to 

 strengthen the supports of structures which might otherwise fall 

 and injure the insects or betray their work. The bat in a lighted 



FIG. ir. Antenna of male Phengodes with portion of ray 

 Greatly enlarged. (Original.) 



