258 HENRY C. MCCOOK. 



the mound, through which it must have been carried from the galleries 

 beneath the surface. Besides this, bits of decayed wood, the needle- 

 like leaves of the pine, pieces of grass, and leaves of shrubs are 

 intermixed with the earth. The soft particles of wood, small and 

 freshly cut, were often found distributed during the night over the 

 surface of hills which Ijad been free from them the day before. There 

 was a similar covering up of the summits of hills with bits of straw 

 which seemed to have been taken from the tufts of grass growing out 

 of the base. I have seen ants upon the grass, as though at work, but 

 have never witnessed the actual severing of the stalk. There can be 

 no doubt however of the fact that these straws are collected (if not 

 cut off), and arranged upon the mounds. 



Ctitiing off Foliage.— That the insects do cut off foliage for such 

 uses may be considered as established by the following fact. A hill 

 kept under constant observation was found covered one morning with 

 the black decayed leaves of a wild indigo plant (Baptisea tinconia), 

 which grew within two feet. The upper part of the shrub had been 

 broken partly oft", probably by one of our party, and was bent over to- 

 wards the mound. The leaves upon this portion were black, upon the 

 rest of the plant green. The black leaves upon the hill had there- 

 fore been cut off from the bruised top, carried to the cone and dis- 

 tributed over two or three square feet of the surface quite thickly. 

 A very great number of these leaves had thus been disposed of In 

 cutting into the hills, however, I do not remember to have found any 

 traces of this surface litter, so completely had it decomposed. I ob-' 

 served it afterwards being covered up ; but the query was raised in 

 my luind, is not its chief use to form an external protection or blanket- 

 ing against the weather? Several of the hills opened showed stones 

 from the size of a man's fist to the size of his head imbedded in the 

 heart of the cone, and raised one or two feet above the ground surface. 

 One such stone is shown in the lower mound PI. V, and another in 

 the angle of the sections at PI. VI. These stones were probably the 

 remains of bombai-dments by truant boys, and had simply been covered 

 over by the patient workers and the hill built up above them. 



Architecture.— What are the methods (and principles shall I say r*) 

 of architecture, by which the Fallow ant prosecutes her immense 

 labors? This was a question which deeply interested my mind. But 

 for the first four days of our stay in camp nothing new or satisfactory 

 presented. The weather was warm and dry, giving no signs of a 

 change. There was little doing in the line of improving the real 



