190 PSYCHOLOGY. 



plain the apparent sizes of the skin-patches, which sizes 

 would consequently not be primitive data but derivative re- 

 sults. 



It seems to me that no evidence of the muscular measure- 

 ments in question exists; but that all the facts may be ex- 

 plained by surface-sensibility, provided we take that of the 

 joint-surfaces also into account. 



The most striking argument, and the most obvious one, 

 which an upholder of the muscular theory is likely to pro- 

 duce is undoubtedly this fact : if, with closed eyes, we trace 

 figures in the air with the extended forefinger (the motions 

 may occur from the metacarpal-, the wrist-, the elbow-, or 

 the shoulder-joint indifferently), what we are conscious of in 

 each case, and indeed most acutely conscious of, is the 

 geometric path described by the fiuger-^^jo. Its angles, its 

 subdivisions, are all as distinctly felt as if seen by the eye ; 

 and yet the surface of the finger-tip receives no impression 

 at all,* But with each variation of the figure, the muscular 

 contractions vary, and so do the feelings which these yield.' 

 Are not these latter the sensible data that make us aware of 

 the lengths and directions we discern in the traced line ? 



Should we be tempted to object to this supposition of 

 the advocate of perception by muscular feelings, that we 

 have learned the spatial significance of these feelings by 

 reiterated experiences of seeing what figure is drawn when 

 each special muscular grouping is felt, so that in the last 

 resort the muscular space feelings would be deriA^ed from 

 retinal-surface feelings, our opponent might immediately 

 hush us by pointing to the fact that in persons born blind 

 the phenomenon in question is even more perfect than in 

 ourselves. 



If we suggest that the blind may have originally traced 

 the figures on the cutaneous surface of cheek, thigh, or palm, 

 and may now remember the specific figure which each pres- 

 ent movement formerly caused the skin-surface to per- 

 ceive, he may reply that the delicacy of the motor percep- 



* Even if the figure be drawn on a board instead of in the air, the vari- 

 ations of contact on the finger's suiface will be much simpler than the 

 peculiarities of the traced figure itself. 



