The third part of the book is concerned, as already stated, with the
development of the understanding. Here it is noticed that memory and
recognition of the mother's voice occurs as early as the second month;
at four months the child cried for his absent nurse; and at eighteen
months he knew if one of ten toy animals were removed. In Preyer's
opinion--and we think there can be no question of its accuracy--the
intelligence of a child before it can speak a word is in advance of that
of the most intelligent animal. He gives numerous examples to prove that
a high level of reason is attained by infants shortly before they begin
to speak, and therefore that the doctrine which ascribes all thought to
language is erroneous.

Highly elaborate observations were made on the development of speech,
the date at which every new articulate sound was made being recorded.
The following appear to us the results under this head which are most
worth quoting.

Instinctive articulation without meaning may occur as early as the
seventh week, but usually not till the end of the first half year. Tones
are understood before words, and vowel sounds before consonants, so
that if the vowel sounds alone are given of a word which the child
understands (thirteen months), it will understand as well as if the word
were fully spoken. Many children before they are six months old will
repeat words parrot-like by mere imitation, without attaching to them
any meaning. But this "echo-speaking" never takes place before the first
understanding of certain other words is shown--never, e.g., earlier than
the fourth month. Again, all children which hear but do not yet speak,
thus repeat many words without understanding them, and conversely,
understand many words without being able to repeat them. Such facts
lead Professor Preyer to suggest a somewhat elaborate _schema_ of