428 MORRIS M. WELLS 



no static sense. Ants are, however, sensitive to gravity and 

 utilize the hints given by the slope of the route. There is (3) 

 no sense of memory of direction as such, for there is no power 

 of orientation except under the influence of the various stimuli 

 mentioned above. 



Wheeler (21) noted that on a certain raid made by the Amazon 

 ant {Polyergus breivceps) the raiders which were fully 200 feet 

 from their own nest, returned at once in the right direction, with 

 their plunder, although for forty feet the path taken was entirely 

 different from the cne over which they had come. 



NOISES MADE BY ANTS 



Ectatoma quadridens, a British Guiana ant (5), makes a squeak- 

 ing sound when it is captured. Daceton armigerum, another 

 tropical ant, when captured and placed in alcohol emits from 

 time to time a sharp click. Azteca schimperi lives in large 

 carton nests built on the r nks of trees (mango). When dis- 

 turbed the ants swarm out, making an audible rustling noise. 

 Paraponera clavata (15) when disturbed comes rushing out 

 making a stridulating noise. Horton (10) says that when the 

 HgCl 2 ant bands are placed around the tree trunks many ants 

 are frequently confined above them in the trees. He has seen 

 these imprisoned ants congregate just above the bands and in 

 some way attract large numbers of free ants which collect on 

 the lower side of the band; there they become so excited that 

 they make desperate attempts to cross the deadly area. The 

 author suggests that stridulations by the confined ants attract 

 and excite the others. 



SWARMING OF ANTS 



Mating. — Gaige (8) records the following dates for the swarm- 

 ing of ants on White Fish Point, Mich. : Cremastogaster lineo- 

 lata, August 27, by hundreds; Myrmica scabrinoides, August 10; 

 Formica sanguinea, July 8-9; many more females than males. 

 Camponotus herculanius, colonies contain winged males and 

 females all summer and swarming occurs from May 14 to August 

 14. Smith (14) saw Prenolepis imparis swarming, March 19, 

 in South Carolina. Wheeler (21) in watching the Amazon ant 

 go out on its slave raids in late July noted that one day a 

 partial marriage flight took place at the same time. This was 



