1890.] The Evolution of Mind. 1005 
with considerable precision, overhand. Stones were also used 
for cracking nuts and other objects, and when the latter were 
resistant, it would leap in the air and bring the stone down with 
great force, and with many grotesque attitudes and grimaces. 
It would draw bolts, lift hooks, and pull out nails which closed 
the door of its cage. I never knew it to open a buckle correctly, 
but it would pull out the threads which fastened the fold of 
leather which held the buckle, and so free itself from the strap. 
On one occasion it imitated the use of the drawing-knife by car- 
penters who were at work in the room in which its cage was kept. 
It secured a square rod of wood, and some fragments of sheet 
tin which had been left near its cage. It carried the wood to a 
shelf in the cage and sat on it, letting it project forward from 
between its legs. It took a piece of tin in both hands, and plac- 
ing the edge across the wood, drew it rapidly backward and for- 
ward on the latter, just as the carpenters use the drawing-knife. 
This action it repeated frequently, with many grimaces and ex- 
pressions of delight. 
It was very expert in the management of its chain. It carried 
it in a coil of its tail over obstructions and objects on which it 
was likely to be caught, quite as carefully and successfully as 
could have been done by a human being. In this it showed its 
intelligence to be superior to that of dogs, cattle, or horses, who 
will wind themselves up when tied, and cannot unwind or extri- 
cate themselves. 
In all these exhibitions the Cebus displayed predication, or 
conception of the consequences of certain causes; eg., the effect 
of being wound up, and the effect of carrying the chain in rela- 
tion to its environment. 
The Cebus was evidently conscious of wrongdoing. When 
detected in some particularly mischievous proceeding his furtive 
and downcast looks showed that he understood the nature of the 
act, and that before any word was spoken. He perfectly under- 
stood the tones of voice of his master, showing alarm or satis- 
faction as the case might be. In attacking a strange animal, as a 
dog, cat, or chicken, he always waited forthe word of command ; 
on receiving it he would spring towards the enemy with loud 
