294 WHEELER. 



did not witness a foray of one of its enormous armies, which often 

 came close to the laboratory and on one occasion actually entered 

 the kitchen and would have overrun the building, had not the cook 

 placed live coals in the path of the oncoming hosts. During the 

 summer of 1919 an army actually took possession of the laboratory 

 and bivouacked for several days in a corner of the storeroom. It is 

 to this species that Beebe's two fascinating articles (1917, 1919) in 

 the Atlantic Monthly refer. The forays seem to be most frequent 

 during the rainy season. At any rate, during the latter part of 

 August 1920, when the rains were becoming somewhat less frequent 

 and copious, fewer armies were encountered in the jungle. 



rf'-- 



^rf^ 



a 



Figure 1. Eciton hurchelli Westw. Heads of soldier (a), large worker (h) 

 and small worker (c). 



So many accurate and detailed accounts of the behavior of hurchelli 

 have been published by such accomplished observers as Bates (1863), 

 Sumichrast (1868), Belt (1874) and Wilhelm Miiller (1886) that I 

 find little of interest to add. Three occurrences, however, mentioned 

 by some of these authors are so striking and so regularly connected 

 with the forays as to deserve long and careful study by some future 

 student at the Tropical Laboratory. These are, first, the beha\aor 

 of the chirping flock of ant-thrushes which accompany the fan-shaped 

 van of the army and feed on the numerous insects and spiders, driven 

 into the open by the feverishly ferreting workers ; second, the swarms 



