ANTHROPOID APES 277 
1907. I feared, however, that the creatures would suffer from 
the loss of the society to which they had been accustomed ; 
so I told off one of my keepers to the sole duty of minding 
them and remaining constantly with them. I hoped thus 
to ward off the ill effects of the tediousness of their life, and 
my hope was amply justified. The animals not only con- 
tinued to thrive on the physical side, but showed great de- 
velopment on the mental side as well. When the cold 
season arrived, I thought it inadvisable to keep them any 
longer in the open waggon-cage and I therefore had a com- 
partment erected in the giraffe house for them to pass the 
winter in. 
Some time after the acquisition of these two orangs, Moritz 
made his appearance. He isa male chimpanzee, about seven 
years old, and he quickly made friends with the orangs. The 
three anthropoids passed the winter together most satisfactorily 
in the giraffe house. We took care to ventilate the building 
thoroughly by means of windows placed high up near the 
roof, so that the temperature there was never tropical. On 
the return of summer, I devised a cage for them from which 
they could emerge at any time into the open air. I still kept 
them in the giraffe house, but I set.aside a portion of the open 
enclosure of the giraffes for their use. The cages in which 
they were confined communicated with the enclosure by 
means of doors, which opened by being merely pushed, 
and then closed again by their own weight. The apes soon 
learnt to push open the doors when they wanted to get out. 
In both the inner cage and the outer enclosure gymnastic ap- 
pliances were set up, so that the creatures should have plenty 
of opportunity for amusing themselves. They are very fond of 
fun, and in their sports I have seen much that is interesting 
and amusing. I ought to say at once that the naturally high 
capacities of anthropoids are greatly enhanced by constant 
association with human beings, and never fully develop except 
in such association. The chimpanzee is far the most vivacious 
and mischievous of the three. He is always the ringleader 
