96 
ANIMAL INTELLIGENCE. 
thickly pressed together, awaiting the word of command from 
the front. When I turned back to the obstacle, I saw with 
astonishment that the loads had been laid aside by more than a 
foot’s length of the column, one imitating the other. And 
now work began on both sides of the branch, and in about half 
an hour a tunnel was made beneath it. Each ant then took up 
its burden again, and the march was resumed in the most per- 
fect order. 
A migration of these ants is thus described by the same 
observer : — 
The road led towards a cocoa plantation, and here J soon 
discovered the building which I afterwards visited daily. As I 
again went thither one day I was met, at a considerable dis- 
tance from the nest, by a closely pressed column coming thence, 
and all the ants laden with leaves, beetles, pupae, butterflies, 
&c. ; the nearer I came to the nest, the greater was the 
activity. It was soon plain to me that the ants were in the 
act of leaving their dwelling, and I walked along the train 
to discover the new abode. They had gone for some distance 
along the old road, and had then made a new one through the 
grass to a cooler place, lying rather higher. The grass on the 
new road was all bitten off close to the ground, and thousands 
were busy carrying the path on to the new building. At the 
new home itself was an unusual stir of life. There were all 
sorts of labourers — architects, builders, carpenters, sappers, 
helpers. A number were busy digging a hole in the ground, 
and they carried out little pellets of earth and laid them 
•together on end to make a wall. Others drew along little twigs, 
straws, and grass-stalks, and put them near the place of build- 
ing. 1 was anxious to know why they had quitted their old 
home, and when the departure was complete, I dug it up with 
a spade. At a depth of about a foot and a half I found several 
tunnels of a large marmot species, the terror of cocoa planters, 
because in making their passages they gnaw off the thickest 
roots of the cocoa plants. The interior of the ant-hill had ap- 
parently fallen in through these mines. Unfortunately I was 
unable to follow further the progress of the new building, for I 
was obliged to leave the next day for San J nan del Sur. When 
I returned at the end of a week the building was finished, and 
the whole colony was again busy with the leaves of the coffee 
plants. 
Harvesting Ants (Atta),— The ants which 3 so far as at 
