ANT STRUCTURES 473 



Bahia and Sao Francisco Eailway, I found the bnrrows exposed in a 

 deep ditch at a depth of 2.1 meters. 



Sampaio, a Brazilian entomologist who has given much attention to 

 the sauba ants, shows one bnrrow as much as 3.5 meters below the sur- 

 face.^^ 



In the State of Sao Panlo, Brazil, the coffee planters have among their 

 employees men whose business it is to fight the saubas. These ant- 

 killers, in the course of their operations against the ants, are said to 

 open out sometimes their underground excavations to a depth of 3.6 

 meters. 



Dr. Jaoquim Lustosa, a Brazilian mining engineer of Lafayette, State 

 of Minas Geraes, Brazil, writes me (June 16, 1909) as follows in regard 

 to the depth to which ants burrow in Minas : "Competent persons assure 

 me that the true ants burrow to a depth of 10 metres or more, and that 

 they exhibit a strange and remarkable intelligence, and that they even 

 cross wide and deep streams by means of tunnels so deep as to avoid the 

 infiltration of the water." 



The length of the tunnels has often been demonstrated by forcing 

 smoke through them. I have myself seen fumes blown into one opening 

 and issuing from others as much as 300 meters away. Mr. Charles J. 

 Dulley, a civil engineer of Sao Paulo, informs me that he has seen fumes 

 driven into the chief nucleus of a colony of saubas, and issuing 183 

 meters away. 



The following statement is given in Mrs. Agassiz's book :^^ 



The saubas 



"make houses bj^ excavating, and sometimes undermine a hill so extensively 

 with their long galleries that when a fire is lighted at one of the entrances 

 to exterminate them, the smoke issues at numerous openings, distant perhaps 

 a quarter of a mile from each other, showing in how many directions they 

 have tunneled out the hill, and that their winding passages communicate with 

 each other throughout." 



On the authority of Eev. H. Clark, Bates says'^* that ants 



"excavated a tunnel under the bed of the River Parahyba, at a place where it 

 is as broad as the Thames at London Bridge. At the Magoary rice mills, near 

 Para, these ants once pierced the embankment of a large reservoir ; the great 

 body of water which it contained escaped before the damage could be repaired. 

 In the Botanic Gardens at Para, an enterprising French gardener tried all he 

 could think of to extirpate the sariba. With this object he made fires over 



32 A. G. de Azevedo Sampaio : Sauva ou Manhu-uara, pp. 22, 52, 64. Sao Paulo, 1894. 



33 Prof, and Mrs. Louis Agassiz : A journey in Brazil, p. 105. Boston, 1868. 

 3* H. W. Bates : Naturalist on the Amazons, 4th ed., pp. 9-15. London, 1875. 



