on erect attitude assumed by gibbon and gorilla, [381], [382]
I
Icelandic language. See [Language]
[Ideas], definition and classification of, [20-39];
as recepts, chap. iii.;
as concepts, chap. iv.;
as general and generic, [38], [39], [68], [69], [276-281], [336], [337];
as abstract, [20-39], [70-80];
of causation in brutes, [58-60],
and in man, [210];