320 MENTAL FACULTIES OF THE BALD CHIMPANZEE. ([June4, 
Houzeau tells us that mules used in tramways at New Orleans have 
to make five journeys from one end of the route to the other before 
they are released, and that they make four of these journeys without 
showing any expectation of being released, but begin to bray towards 
the end of the fifth’. Lastly, the keeper of the Sea-Lions now 
in the menagerie has recently taught one of these animals to ‘* count ” 
as far as five. His method is to throw pieces of fish in regular 
succession, which the animal catches one by one. He throws them 
in series of fives, and, before the commencement of any series, he 
tells the seal to miss the first, the second, the third, the fourth, or the 
fifth, as the on-lookers may dictate: the Sea-Lion thereupon makes 
no attempt to catch the member of the series thus verbally indicated. 
It is only a day or two ago, however, that I witnessed this perform- 
ance, and as yet I am not satisfied that the Sea-Lion really ‘ counts,” 
because it appears to me probable that the keeper may unintentionally 
make some slight differeuce in his manner of throwing the piece 
of fish which he expects the Sea-Lion to miss, and that it is really 
this slight difference in the manner of throwing which the seal per- 
ceives and acts upon. Therefore, I intend to get an arrangement 
fitted up whereby the pieces of fish shall be thrown mechanically. 
But, whatever the result of this experiment may be, I think 
there can now no longer be any question that it lies within the capa- 
city of animal intelligence to ‘* count ” correctly (in tie sense already 
explained) as far as five, and even to show a well-marked apprecia- 
tion—although progressively a more and more uncertain one—of 
numbers lying between five and ten. 
The only other direction in which I have thus far subjected the 
Chimpanzee to psychological experiment has been in that of attempting 
to teach her the names of colours. It appeared to me that if I could 
once succeed in getting her thoroughly well to know the names of 
black, white, red, green, or blue, a possible basis might have been 
laid for many further experiments wherein these five colours could 
have been used as signs of artificially associated ideas. The result, 
however, of attempting to teach her the names of colours bas been 
so uniformly negative, that I am disposed to think the animal must be 
colour-blind. It is perhaps desirable to state the facts which have 
led me to entertain this their most probable interpretation. 
The method adopted in these experiments was to obtain from the 
importers of oriental matting a number of brightly and uniformly 
coloured pieces of straw—each piece being either white, black, red, 
ereen, or blue. Offered the straws two by two of different colours 
on each occasion, the ape was invited to select the straw of the 
colour named from the one whose colour was not named, and, of 
course, on choosing correctly was rewarded with a piece of fruit. 
In this way she quickly learnt to distinguish between the white 
straws and the straws of any other colour; but she never could be 
taught to go further. Now the distinction between the white 
straws and the straws of any other colour is a distinction which can 
be drawn by an eye that is colour-blind; and from the fact that 
1 Fac. Ment. des Anim. tom. ii. p. 207. 
