524 THE AMERICAN NATURALIST. | [Vor. XXXV. 
the pavement or even on the gravel cone.! On the other hand, 
I have counted on a single pavement no less than ten of the 
balls of dung abandoned by the Canthons (C. /evis) which 
had been driven away from their precious charges by the ants. 
Malodorous beetles like Chauliognathus scutellaris when placed 
on the nests are seized by the ants, at once carried to the edge 
of the pavement, and dumped over the boundary. Man and 
the larger domestic animals are soon attacked when they stand 
within the disk, and the horned toad, which seems to feed very 
largely on these ants, is treated in the same manner. (See 
Edwards, '96.) 
II. PanaBIOSIS. 
Forel (99) introduced the term “ parabiosis” to designate 
a peculiar form of compound nest with inosculating galleries, in 
which different species of ants have their households strangely 
intermingled but not actually blended. Only one typical case 
of this description is known, but some remarkable nests in 
tillandsias recently observed by me in Mexico are in certain 
respects similar to the case described by Forel, so that they 
may be included, at least provisionally, in the same category. 
9. Dolichoderus and Cremastogaster. 
The interesting observations made by Forel ('99, pp. 380, 381) 
in the United States of Colombia during the spring of 1896 are 
here translated in full : 
“I frequently observed, originally in the neighborhood of 
Santa Martha, two species of ants belonging to different 
genera and even subfamilies, a Dolichoderus and a Cremasto- 
gaster, both shining black, the former very large, noticeably 
larger than the latter, usually running in the very same files, 
both over the ground and on the trees and undergrowth, in 
the most perfect amity. The files were very long and dense, 
so that the ants met and elbowed one another continually. The 
two species went foraging on the trees, the Cremastogaster 
searching mainly for plant lice and Coccidz, the Dolichoderus 
1 Several years ago I observed another species of Eleodes similarly engaged vs 
the nests of P. occidentalis in Wyoming. 
