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which actively pursue and capture their prey. They are to be 
described as predatory, while the keleps are merely predaceous, and 
like many other predaceous animals their movements are slow and 
deliberate except when they make a final spring to seize their game. 
The slow movements of the kelep thus conduce to its efficiency as a 
hunting insect, and may be looked upon as an evidence of specializa- 
tion in this direction. Odontomachus and the Texan Poneride, so 
far as observed, are quicker and more excitable under ordinary cir- 
cumstances, but they seem not to have developed any such skill in 
capturing quick-moving insects. The similarity of the keleps to 
the drivers is greater, however, when the colony moves and the eggs, 
larvee, pups, cocoons, and queens are carried over to the new burrow. 
In one instance a few of the workers refused to leave the old nest. 
but the majority would not permit the colony to be divided in this 
way and finally captured and carried off the unwilling members in 
the same way that the queen is removed. One of the Brazilian rela- 
tives of the kelep is described by Bates as marching about in the 
forests in a manner which must give them a considerable resemblance 
to the drivers.* 
‘Tt is true, of course, that the keleps and the drivers are very dis- 
tinct, but careful comparison will show that the differences are in 
degree rather than in kind. They represent possible developments 
from the same primitive system of organization, while to find a 
common starting point with the ants it may be necessary to go back 
to the nonsocial stage. Structurally, too, the keleps are very differ- 
ent from the drivers, but the genus Cerapachys and its allies are 
‘referred by some authors to the Poneridxe and by others to the 
Dorylide. It should be no more surprising that some of the habits 
of the true ants should be approximated by other groups of inde- 
pendent origin than that the bees and wasps, or that the true ants 
and the termites, should be so similar. 3 
The idea that any existing group of organisms has given rise to 
another group is generally, and probably always, erroneous. With 
respect to any given character, one group may remain primitive while 
another has advanced, but nothing organic is stationary, and the fact 
that a plant or animal is primitive in one respect may well be taken 
as a suggestion that good progress has been made in some other, 
Looked upon as ants, the kelep and its relatives are undoubtedly 
primitive, since they are more like wasps than like other ants, but the 
a‘* We were amazed at seeing ants an inch and a quarter in length and stout 
in proportion marching in single file through the thickets. These belong to the 
species called Dinoponera grandis. Its colonies consist of a small number of 
individuals, and are established about the roots of slender trees. It is a sting- 
ing species, but the sting is not so severe as in many of the smaller kinds.”’— 
Bates, H. W., 1875, Naturalist on the River Amazon, p. 9, ed. 4. 
