NOTES OF A BOTANIST 
all, with the exception of the herbaceous species, 
are infested by ants. The order is Polygoneae ; 
the ant -infested species belong to the genera 
Triplaris, Coccoloba, Campderia, Symmeria, and 
Rupprechtia ; and the exceptions are species of 
Polygonum, some of them closely resembling 
common European species. All, both trees and 
herbs, grow in moist situations, and most of them 
on lands subject to periodical inundations. Not 
only is every lignescent Polygonea a habitation 
for ants, but the whole of the medulla of every 
plant, from the root nearly to the growing apex of 
the ramuli, is scooped out by those insects. The 
ants make a lodgment in the young stem of the 
tree or shrub, and as it increases in size and puts 
forth branch after branch, they extend their hollow 
ways through all its ramifications. They appear 
to belong all to a single genus, and are long and 
slender, with a fusiform, very fine-pointed, dark- 
coloured, shining abdomen,, and they all sting 
virulently. They are known in Brazil by the name 
of *'Tachi" or " Tac^ba," and in Peru by that of 
Tangarana " ; and in both countries the same 
name is commonly applied to any tree they infest 
as to the ants themselves. 
A few trees and shrubs of other orders are 
similarly infested by Tachi ants ; such as Platy- 
miscium (Vog.) in Leguminosae, Tachia (Aubl.) in 
Gentianeae, and Mabea (Aubl.) in Euphorbiaceae. 
Tripla7^is siirina77tensis, Camb., a Polygoneous 
tree of very rapid growth, reaching at maturity a 
hundred or more feet in height, and conspicuous 
from afar when in fruit from the abundance and 
bright red colour of its enlarged shuttlecock -like 
