Rock-Carving 169 
near the base of these cliffs there was a carving of a bull, and 
that the place was enchanted. I had heard in other parts 
stories of bulls being engraved or painted on rocks, but was 
very doubtful about their being true, as, up to the advent of 
the Spaniards, the Indians of Central America had never 
seen any cattle; and since the conquest they appear to have 
entirely given up their ancient practice of carving on stone, 
whilst the Spaniards and half-breeds have not learnt the 
art; so that I have never seen a single carving in the central 
departments that could be ascribed to a later period than the 
Spanish conquest. 
Tired and hungry though we were, I was determined to put 
this story to the test; so Velasquez and I climbed up to the 
cliffs, and searched all round them, but could find no carving. 
At one place there was a large black stain on the cliff, pro- 
duced by the trickling down of water from above, and I 
afterwards learnt that this stain at a distance somewhat 
resembled a bull, and a little imagination completed the like- 
ness. The lady of the house where we stayed at Matagalpa 
assured us she had seen it, and that everything appertaining 
to a bull was there. This she insisted on with a minuteness 
of detail rather embarrassing to a fastidious auditor. 
Clambering down the rocks, we reached our horse and 
mule, and started off again, passing over dry weedy hills. 
One low tree, very characteristic of the dry savannahs, I 
have only incidentally mentioned before. It is a species of 
acacia, belonging to the section Gummuifere, with bi-pinnate 
leaves, growing to a height of fifteen or twenty feet. The 
branches and trunk are covered with strong curved spines, 
set in pairs, from which it receives the name of the bull’s- 
horn thorn, they having a very strong resemblance to the 
horns of that quadruped. These thorns are hollow, and are 
tenanted by ants, that make a small hole for their entrance 
and exit near one end of the thorn, and also burrow through 
the partition that separates the two horns; so that the one 
entrance serves for both. Here they rear their young, and 
in the wet season every one of the thorns is tenanted; and 
hundreds of ants are to be seen running about, especially 
over the young leaves. If one of these be touched, or a 
branch shaken, the little ants (Pseudomyrma bicolor, Guer.) 
swarm out from the hollow thorns, and attack the aggressor 
