Chap. II. 
MENTAL POWERS. 
59 
plan with ours, and which are used as a means of commu- 
nication, it was obviously probable, if the power of com- 
munication had to be improved, that these same organs 
would have been still further developed ; and this has 
been effected by the aid of adjoining and well-adapted 
parts, namely the tongue and lips . 40 The fact of the 
higher apes not using their vocal organs for speech, no 
doubt depends on their intelligence not having been 
sufficiently advanced. The possession by them of organs, 
which with long-continued practice might have been 
used for speech, although not thus used, is paralleled by 
the case of many birds which possess organs fitted for 
singing, though they never sing. Thus, the nightingale 
and crow have vocal organs similarly constructed, these 
being used by the former for diversified song, and by 
the latter merely for croaking . 41 
The formation of different languages and of distinct 
species, and the proofs that both have been developed 
through a gradual process, are curiously the same . 42 
But we can trace the origin of many words further 
back than in the case of species, for we can perceive 
that they have arisen from the imitation of various 
sounds, as in alliterative poetry. We find in distinct 
languages striking homologies due to community of 
descent, and analogies due to a similar process of 
40 See some good remarks to this effect by Dr. Maudsley, 4 The 
Physiology and Pathology of Mind/ 1868, p. 199. 
41 Macgillivray, ‘Hist, of British Birds/ vol. ii. 1839, p. 29. An 
excellent observer, Mr. Blackwall, remarks that the magpie learns to 
pronounce single words, and even short sentences, more readily than 
almost any other British bird ; yet, as he adds, after long and closely 
investigating its habits, he has never known it, in a state of nature, 
display any unusual capacity for imitation. 4 Researches in Zoology/ 
1834, p. 158. 
42 See the very interesting parallelism between the development of 
speech and languages, given by Sir 0. Lyell in 4 The Geolog. Evidences 
of the Antiquity of Man/ 1863, chap, xxiii. 
