APPENDIX. 
415 
ing the young bananas, orange, and mango trees of their leaves. I 
followed up the paths of the invading hosts to their nest, which was 
about one hundred yards distant, close to the edge of the forest. 
The nest was not a very large one, the low mound of earth covering 
it being about four yards in diameter. At first I tried to stop the 
holes up; but fresh ones were immediately opened out. I then dug 
clown below the mound and laid bare the chambers beneath, filled 
with ant-food and young ants in every stage of growth. But I soon 
found that the underground ramifications extended so far and to so 
great a depth, whilst the ants were continually at work making fresh 
excavations, that it would be an immense task to eradicate them by 
such means ; and notwithstanding all the digging I had done the first 
day, I found them as busity at work as ever at my garden, which they 
were rapidly defoliating. At this stage our medical officer, pv. J. H. 
Simpson, came to my assistance, and suggested the pouring car¬ 
bolic acid, mixed with water, down their burrows. The suggestion 
proved a most valuable one. We had a quantity of common brown 
carbolic acid, about a pint of which I mixed with four buckets of 
water, and, after stirring it well about, poured it down their burrows. 
I could hear it rumbling down to the lowest depths of the formicarium, 
four or five feet from the surface. The effect was all that I could 
have wished ; the marauding parties were at once drawn oft from my 
garden to meet the new danger at home. The whole formicarium was 
disorganized. Big fellows came stalking up from the cavernous regions 
below, only to descend again in the utmost perplexity. 
“ Next day I found them busily employed bringing up the ant-food 
from the old burrows and carrying it to a new one a few yards dis¬ 
tant ; and here I first noticed a wonderful instance of their reasoning 
powers. Between the old burrows and the new one was a steep slope. 
Instead of descending this with their burdens, they cast them down 
on the top of the slope, whence they rolled down to the bottom, where 
another relay of laborers picked them up and carried them to the new 
burrow. It was amusing to watch the ants hurrying out with bundles 
of food, dropping them over the slope and rushing back immediately 
for more. They also brought out great numbers of dead ants that the 
fumes of the carbolic acid had killed. A few days afterwards, when 
I visited the locality again, I found both the old burrows and the new 
one entirely deserted, and I thought they had died off; but subsequent 
events convinced me that the survivors had only moved away to a 
greater distance. It was fully twelve months before my garden was 
again invaded. I had then a number of rose-trees, and also cabbages 
