ANTS AND SOME OTHER INSECTS. 4! 



elation the missing remnant of a visual spatial image. For this 

 reason, too, the visual sensations are preeminently associative or 

 relational in space, to use Spencer's expression. For the same 

 reason the insane person so readily exhibits halucinations of com- 

 plicated spatial images in the visual sphere. This would be im- 

 possible in the case of the olfactory sense. 



Similarly, the organ of Corti in the ear gives us tone or sound 

 scales in accurate time-sequence, and hence also associations of 

 sequence much more perfectly than the other senses. Its associa- 

 tions are thus in the main associations of sequence, because the 

 end-apparatus registers time-sequences in time-intervals and not 

 as space images. 



The corresponding cortical receptive areas are capable, in the 

 first instance, merely of registering what is brought to them by the 

 sense-stimuli and these are mainly associated spatial images for 

 sight and tone or sound-sequences for hearing. 



Let us consider for a moment how odors strike the mucous 

 membranes of our choanae. They are wafted towards us as wild 

 mixtures in an airy maelstrom, which brings them to the olfactory 

 terminations without order in the inhaled air or in the mucous of 

 the palate. They come in such a way that there cannot possibly 

 be any spatial association of the different odors in definite relation- 

 ships. In time they succeed one another slowly and without order, 

 according to the law of the stronger element in the mixture, but 

 without any definite combination. If, after one has been inhaling 

 the odor of violets, the atmosphere gradually becomes charged 

 with more roast meat than violet particles, the odor of roast suc- 

 ceeds that of violet. But nowhere can we perceive anything like a 

 definitely associated sequence, so that neither our ideas of time nor 

 those of space comprise odors that revive one another through as- 

 sociation. By much sniffing of the surface of objects we could at 

 most finally succeed in forming a kind of spatial image, but this 

 would be very difficult owing to man's upright posture. Neverthe- 

 less it is probable that dogs, hedge-hogs, and similar animals ac- 

 quire a certain olfactory image by means of sniffing. The same 

 conditions obtain in the sphere of taste and the visceral sensations 



