Inheritance of Acquired Characters 241 
Spencer thinks that “some of the best illustrations of 
functional heredity are furnished by mental characteristics.” 
He cites the musical faculty as one that could not have been 
acquired by natural selection, and must have arisen through 
the inheritance of acquired modifications. The explanation 
offered is “that the habitual association of certain cadences 
of speech with certain emotions has clearly established in 
the race an organized and inherited connection between 
such cadences and such emotions, . . . and that by the con- 
tinued hearing and practice of melody there has been gained 
and transmitted an increasing musical sensibility.” But a 
statement that the results have been acquired in this way 
does not supply the proof which the theory is in need of; 
neither does it follow that, because the results cannot be 
explained by the theory of natural selection, therefore, they 
must be explained by the Lamarckian theory. 
The clearest proofs that Spencer finds of the inheritance 
of acquired characters are in the well-known experiments of 
Brown-Séquard. These experiments will be more fully dis- 
cussed below. Amongst the other morbid processes that 
Spencer thinks furnish evidence in favor of this view, are 
cases of a tendency to gout, the occurrence of mental tricks, 
musical prodigies, liability to consumption, in all of which 
cases the fundamental distinction between the inheritance of 
an acquired character and the inherited tendency toward a 
particular malady is totally ignored. 
Twenty-seven years later (in 1893) Spencer took up the 
open challenge of the anti-Lamarckian writers, and by bring- 
ing forward a number of new arguments attempted to rein- 
state the principle of the inheritance of acquired characters. 
His first illustration is drawn from the distribution of the 
sense of touch in different parts of our bodies. Weber’s ex- 
periments have shown that if the sharp points of a pair of 
compasses are applied to the tips of the forefingers, the sen- 
sation of two separate points is given when the points are 
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