42 ANTS AND SOME OTHER INSECTS. 



for the same reasons. None of these senses furnish us with any 

 sharply defined qualitative relations either in space or time. On 

 this account they furnish by themselves no associations, no true 

 perceptions, no memory images, but merely sensations, and these 

 often as mixed sensations, which are vague and capable of being 

 associated only with associative senses. The hallucinations of 

 smell, taste, and of the splanchnic sensations, are not deceptive 

 perceptions, since they cannot have a deceptive resemblance to ob- 

 jects. They are simply paraesthesias or hyperaesthesias, i. e., path- 

 ological sensations of an elementary character either without ade- 

 quate stimulus or inadequate to the stimulus. 



The tactile sense furnishes us with a gross perception of space 

 and of definite relations, and may, therefore, give rise to hallucina- 

 tions, or false perceptions of objects. By better training its asso- 

 ciative powers in the blind may be intensified. The visual sensa- 

 tions are usually associated with tactile localisations. 



Thus we see that there is a law according to which the psy- 

 chology of a sense depends not only on its specific energy but also 

 on the manner in which it is able to transmit to the brain the rela- 

 tions of its qualities in space and time. On this depends the 

 knowledge we acquire concerning time and space relations through 

 a particular sense and hence also its ability to form perceptions 

 and associations in the brain. More or less experience is, of course, 

 to be added or subtracted, but this is merely capable of enriching 

 the knowledge of its possessor according to the measure of the re- 

 lations of the particular sense-stimuli in space and time. 



I would beg you to hold fast to what I have said and then to 

 picture to yourselves an olfactory sense, i. e. , a chemical sense 

 effective at a distance and like our sense of smell, capable of re- 

 ceiving impressions from particles of the most diverse substances 

 diffused through the atmosphere, located not in your nostrils, but 

 on your hands. For of such a nature is the position of the olfac- 

 tory sense on the antennal club of the ant. 



Now imagine your olfactory hands in continual vibration, touch- 

 ing all objects to the right and to the left as you walk along, thereby 

 rapidly locating the position of all odoriferous objects as you ap- 



