1901.] NATURAL SCIENCES OF PHILADELPHIA. 447 



I have seen queeulcss workers break up and feed alieu j)upie to 

 the larvie they were roaring, but wlieu they had no larva- they 

 took excellent care of pupa^ from the same alien stock. As one 

 pupa will furnish an ample meal to a great number of larvie, there 

 may be much economy in thus utilizing an alien pupa that appears 

 unseasonably in their nursery. 



An exj^lanatiou of the somewhat erratic behavior (»f the ants 

 toward alien young will be suggested in a subsequent paragraph. 



In many of the experiments made to test the power of these ants 

 in recognizing those of their own colony, I used a small number 

 of ants in each cell, and, without marking the ants, I could, by 

 choosing those of one shade from one colony and those of another 

 shade from another colony, always identify the colony to which 

 any ant used in the experiment had originally belonged, and could 

 invariably return her to her own. 



The power of Stenamma fidvum piceum to recognize another of 

 her own colony is not destroyed by freezing and thawing either 

 one or both of the individuals. 



Neither is it destroyed by merging one or both for an instant in 

 alcohol, in diluted oil of anise-seed or of bergamot, in tincture of 

 valerian or of asafoetida. The adult workers will survive dipping 

 in eighty per cent, alcohol or in the above-mentioned oils and tinc- 

 tures duly diluted. On returning the dipped workers to their 

 colony they are nut attacked as are aliens, though they may be for 

 a time avoided, and on recovering from the bath they join their 

 comrades in the common vocations of the nest. 



I repeated one of the experiments of Bethe and obtained with 

 my ants results similar to his. When I mashed ants of colony 

 C—e and with the juices thus obtained smeared ants of the alien 

 colony B-b, the C—e colony received the smeared ants without hos- 

 tility, and the smeared ants exhibited the trepidation usual at 

 finding themselves in an alien nest. Likewise, ants from the C-e 

 colony, freshly smeared with the juices of B-b ants, were not 

 attacked in the B-b nest, but they were evidently terrified in being 

 there. 



I then smeared a small number of B-b ants with the juices of 

 C-e ants, and put them into a new Petri cell with an equal number 

 of uusmeared C-e ants; and I smeared a small number of C-e 

 ants with the juices of B-b ants and put them into a new Petri 



