ACROSS THE ANTIOQUIAN GOLD-FIELDS 119 



and waited a few hours until the ant army had completed 

 its work and gone on its way. The natives welcome these 

 visits as the ants act as scavengers and rid the house of 

 vermin. 



While at Puerto Yaldivia we were presented with a young 

 night monkey not larger than a good-sized mouse. It was 

 a most interesting pet, and readily took to a diet of con- 

 densed milk, which it drank from a spoon. My companion, 

 to whom the little animal belonged, kept it on the window- 

 Bill, from which point of vantage it took a lively interest in 

 all that occurred within its range of vision. It so happened 

 that there was a very small crack in the sill, and this proved 

 to be a matter of the utmost concern to the tiny monkc\ . 

 Hundreds of times each day it crept timidly to the crack 

 and peered down into it anxiously, although there was only 

 darkness below. When we held the pelt of an animal near 

 it paid no attention whatever to it, with the single excep- 

 tion of the skin of one of its species, which it recognized 

 immediately, and to which it clung tenaciously. When we 

 left the hot climate of the Lower Cauca and started on the 

 return journey to Medellin the little creature was unable 

 to withstand the cold of the higher altitude and died. 



The puipose of our zoological exploration of this section 

 of Antioquia was to secure material that would throw light 

 on the geography of the country farther north; for, beyond 

 the general knowledge that the junction of the Cauca and 

 the Magdalena mark the breaking down of the Cordillera 

 Central, we knew comparatively little of a definite charac- 

 ter about this part of Colombia. It was not until several 

 months later that our work farther west — on the Paramillo 

 and the Rio Sucio — provided the material which, viewed 

 from a distributional standpoint, furnished the clews that 

 aided very materially in solving our problem. 



