216 
ORIGIN OF LIFE IN AMERICA 
Columbia, the third in the north-east.* * * § Honey-ants, at least 
certain members of their colonies, possess the faculty of 
storing quantities of honey within their bodies, which swell 
up to a great size, and on that account are somewhat remark¬ 
able objects. In North America two species of honey-ants 
occur, namely, Myrmeocystus melliger and M. mexicanus, 
both being confined to Mexico, Arizona and the neighbouring 
regions. The other species of the genus Myrmeocystus in¬ 
habit the Mediterranean Region and further east as far as 
central Asia.f In southern Europe a soft, velvety ant is 
found belonging to the genus Liometopum. The same species 
was likewise supposed to inhabit California, but Professor 
Wheeler ;j; found that although the two forms are very 
closely related, the American differs slightly in shape and 
even in its habits from the European species. Whereas the 
former constructs its nests underground, the latter utilises 
for that purpose the abandoned burrows of beetles under the 
bark of trees. Hence he calls the American ant, Liometopum 
apiculatum. It is limited in its range to California and 
Mexico. Only two other species of Liometopum are known. 
One, (L. microcephalum), as I mentioned, lives in southern 
Europe, the other (L. lindgreeni) in Assam. It is not often 
that we actually become acquainted with the extinct ancestors 
of such interesting invertebrates as these. But fossil forms 
of Liometopum have been discovered, according to Hr. Hand- 
lirsch§ in the Lower Miocene of Croatia and the Oligocene of 
Colorado. Even in Tertiary times the genus seems to have 
occupied much the same localities as it does to-day; it only 
spread formerly further north no doubt owing to the more 
favourable climatic conditions then prevailing. 
Many other similar instances might be quoted. I will only 
allude to one more. The two well-known European ants 
Formica cinerea and Formica rufibarbis had been reported 
from the south-western States of North America, but Pro¬ 
fessor Emery doubted the correctness of the identification 
until Professor Wheeler sent him American specimens. Both 
* Emery, 0., “ Nordamerikanische Ameisenfauna,” p. 299. 
t Wheeler, W. M., “Iloney Ants,” p. 347. 
| Wheeler, W. M., “ North American Liometopum,” p. 321. 
§ Handlirsch, A., “ Die Eossilen Insekten,” p. 870. 
