HARVESTING ANTS. 
99 
harvest to the nest is very long, they make regular depots for 
their provisions under large leaves, stones, or other suitable 
places, and let certain workers have the duty of carrying them 
from depot to depot. 
Buchner ( loc . cit. p. 101) also makes the following 
references to the statements of previous observers : — 
The subterranean workers of this remarkable genus are very 
clever. The Rev. H. Clark reports from Rio de Janeiro, that 
the Sa-ubas have made a regular tunnel under the bed of the 
river Parahyba, which is there as broad as the Thames at 
London, in order to reach a storehouse which is on the opposite 
bank. Bates tells us that close to the Magoary rice- mills, near 
Para, the ants bored through the dam of a large reservoir, and 
the water escaped before the mischief could be remedied. In 
the Para Botanical Gardens an enterprising French gardener 
did everything he could to drive the Sa-ubas away. He lit fires 
at the chief entrances of their nests, and blew sulphur vapour 
into their galleries by means of bellows. But how astonished 
was Bates when he saw the vapour come out at no less a dis~ 
tance than seventy yards ! Such an extension have the sub- 
terranean passages of the Sa-ubas. 
The recognition of the principle of the division of 
labour, which is shown by the above observations, is further 
corroborated by the following quotation from Belt : — 
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 labourers 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. 
The same thing has been observed, as already stated, 
of the leaf-cutting ants — those .engaged in cutting fre- 
quently throwing dowm the fragments of leaf which they 
cut to the carriers below. The prevalence of this habit 
among various species of ants therefore renders credible 
the following statements of Vincent Gredler of Botzen 
which are thus recorded in 6 der Zool. Gart., 5 xv. p. 434 : — 
In Herr Gredler’s monastery one of the monks had been 
accustomed for some months to put food regularly on his window* 
