1903.] NATURAL SCIENCES OF PHILADELPHIA. 493 



rooms as serenely as did the ants in the dark nests, with whom they 

 were frequently compared. In the white nest the ants did not bring 

 their young out upon the sponges, in bright dayhght, until the end of 

 February. 



In the orange nest, on the contrary, the ants behaved from the be- 

 ginning as did those in the dark nest, never huddhng in the haUways 

 nor seeking the shade of the walls. They often clustered in the most 

 highly illuminated portions of the area. All the actions of the ants 

 indicated that they were insensible to the red and green rays.^ 



As the nests were new and nearly ahke in structure, temperature and 

 humidity, there seems to have been no reason other than that which 

 lay in the difference in light-rays, for the difference in the behavior of 

 the ants in the different nests, those in the white and the violet nests 

 behaving nearly alike, and those in the orange and the dark nests be- 

 having wholly alike. The point to be here noted is that the ants in the 

 white and the violet nests learned to be unafraid of the rays that at 

 first drove them into corners. After ten months' exposure to these 

 rays they were still sensitive to them, preferred shelter from them, and 

 would soon move to a room of which I changed the roofing to such as 

 covered either the orange or the dark nest; but they appeared to have 

 learned that those light-rays were innocuous. Not only, then, can 

 these ants become acquainted with human beings, lose fear of 

 them and cease to sting them; not only can they become acquainted 

 with ants of alien famihes and thereupon cease to quarrel with them, 

 but they can become unafraid of certain light-rays and adjust their 

 behavior to conditions to which they were instinctively averse. They 

 are susceptible to education through the eye as well as through the 

 sense of smell.^ 



^Formica subsericea, Cremastogaster Uneolata, Lasius umbratus and Lasius 

 latipes behave in the same manner toward these rays. 



« Something that appears purposeful in the behavior of mv ants is their carry- 

 ing ot morsels of hickory-nut or other dry substance and dotting with it the sur- 

 tace ot a lump of Turkish paste or other viscid sweet that they like to eat They 

 then stand with clean feet on the stepping stones that they have laid and lap the 

 ,,yj9°^\ Oftentimes the sticky sweet is the oniv one among several kinds 

 ot food in their food-room that is flecked by these bits of nut. It may be that 

 ants enaged in carrying morsels of food come upon something more luscious and 

 drop the former in order to enjoy the latter. They are apt to give special atten- 

 tion to any new dainty. i a ^ 



Dr. Wheeler, on p. 18 of the paper referred to in note 3, says of his Leptothorax 

 that isolation brought out an instinct which is common to all ants known to 

 me except Pobjgerus . . the instinct that impels them to collect dead sister 

 *" ^5 w^ particles of earth, etc., and to deposit them on liquid food in the man- 

 ger. When cleaning up their dwellings, as my ants do, carrying particles to 

 the rubbish-pile, as is their wont, diversion of their atteiition wiU often 

 cause them as it will cause monkeys, to drop the thing they carrv. The same or 

 ^u u ^^J' "'""^ P'^^5 "P the dropped particle, if it be not bevond recovery 

 1 hey hold more tenaciously to the young that they have in charge. 



