BEHAVIOR OF ANTS AND MYRMECOPHILES 435 



bricks) the error ranged from one-sixth to nine-tenths of the 

 distance. On a longer journey the error was still greater. The 

 start in a direction the reverse of the line of march in the out- 

 ward journey, even when not toward the nest, and on different 

 kinds of material, offers additional evidence that the home- 

 going ant is influenced little by sight or the sense of touch. 



Cornetz (7) repeated the experiment of turning a disc on 

 which an ant (Myrmecocystus (Cataglyphis) bicolor) was feeding. 

 The disc in this case was a large plate, containing sugar as bait. 

 Each time the ant, when it was through feeding and had a load 

 of the food, immediately oriented itself in the direction toward 

 its nest-entrance, though the disc had been turned 180 or 270 . 

 The podometric sense, according to Cornetz, will not explain 

 the return of the ant, both because "a podometer is no com- 

 pass" and because the route taken by the returning insect is 

 not the same as the outgoing trip. He answers the question, 

 "How do ants find their way," by stating that they do not 

 find their way. It is not necessary. They are guided by some 

 internal impression received on the outgoing trip. Just what 

 this is, he does not pretend to understand, but he believe that 

 it is neither touch, smell nor sight, nor a combination of these, 

 but something peculiar, possessed by all ants. 



Crawley (11) studied parthenogenetic reproduction in Lasius 

 niger, with colonies confined in artificial nests. It has long been 

 known that under certain conditions, generally when no queen 

 is present, worker ants are capable of laying unfertilized eggs 

 that develop parthenogenetically. Some observers have con- 

 cluded that only males are produced from these worker-laid 

 eggs, but in 1902 a queenless colony of Lasius niger, kept under 

 observation by Reichenbach, reared some three hundred workers 

 and two or three dozen males from unfertilized eggs, and Wheeler 

 in 1903 recorded similar results obtained by Mrs. Comstock with 

 Lasius niger var. americanus. On the other hand, Janet, who 

 made careful experiments with no less than thirty queenless 

 colonies under varied conditions, succeeded only in getting 

 males. Into a nest of Lasius niger that had lost its queen through 

 accident, Crawley placed a queen of Lasius umbratits which was 

 immediately adopted. Although this queen deposited many 

 fertile eggs, for two years none of the young reached maturity, 

 as they were eaten by the niger workers; thereafter the few 



