4o6 NOTES OF A BOTANIST 
of the Andes. Their case is parallel to that of 
the lake-dwellers of the mouth of the Orinoco 
and the inundated savannas of Guayaquil, whose 
descendants must needs elevate their houses on 
stages six feet or more in height, although nowa- 
days erected on rising ground far beyond the 
reach of river floods or ocean-tides. We call this 
"instinct" in the case of ants, "inherited custom" 
in the case of men ; yet there is obviously no 
difference. 
There are numerous instances of the effects of 
Ant-agency in the plants of Tropical America, not 
reducible to any of the foregoing sections. At 
Tarapoto, in the Andes of Maynas, a prickly 
suffruticose Solanum, with pinnate leaves, is 
frequent in sandy ground. The fruit is a small 
scarlet edible berry, tasting like that of Physalis. 
The very prickly calyx persists with the fruit, and 
is dilated into a wide cup which holds the water of 
rains, for whose sake it is visited by fire-ants that 
have their burrows in the sand. The contained 
water is slightly mucilaginous, and possibly, after 
standing a while, partakes of the flavour of the berry 
that is partially immersed in it. After a shower, the 
ants may be seen crowding on the inner edge of 
the calyx and sipping the liquid; but in dry weather 
they fill the calyx, bent apparently on extracting the 
last drop. The consequence of this crowding into 
the calyx is to sustain and augment the inflation. 
The bulging, gummy, water- holding leaf- bases of 
many epiphytal Bromels seem to owe those 
properties to the same influence, for they are 
commonly infested by ants, whose papery nest, 
indeed, often envelops the root of the plant. 
