1898] MR HERBERT SPENCERS BIOLOGY 383 
peripheral nerve-endings. There is no spot on the skin that is not 
sensitive to the touch of a pencil-point. And we do not yet know 
the limits within which education and practice may refine the appli- 
cation of central powers of discrimination within little-used areas. 
The facts which Mr Spencer adduces may be in large degree due to 
individual experience ; discrimination being continually exercised in 
the tongue and finger-tips, but seldom on the back or breast. We 
need a broader basis of assured fact. 
It may here be parenthetically noted that Mr Spencer’s conten- 
tion that the nervous system is the result of direct equilibration is 
difficult to square with the embryological discovery that the axis- 
cylinders of the afferent spinal nerves take their origin in the nerve- 
crest (which differentiates into the ganglia on the dorsal roots) and 
grow outwards to their distribution in the skin or elsewhere. 
A third line of evidence on which Mr Spencer relies is that 
supplied by vestigial organs, which, he contends, must be due to 
dwindling through disuse. But the explanation is beset with diffi- 
culties. Is there any evidence that a structure really dwindles 
through disuse in the course of individual life? Let us be sure of 
this before we accept the argument that vestigial organs afford 
evidence that this supposed dwindling is inherited. The assertion 
may be hazarded that, in the individual life, what the evidence shows 
is that, without due use, an organ does not reach its full functional 
or structural development. If this be so, the question follows : How 
is the mere absence of full development in the individual converted 
through heredity into a positive dwindling of the organ in question ? 
In our present state of ignorance we can only adopt the form used 
by Mr Spencer and say: No reply. 
It will be understood that the foregoing considerations are urged, 
not in support of one hypothesis or in opposition to another, but in 
advocacy of suspended judgment, of calm and impartial weighing of 
evidence, and, above all, of further observation and experiment. 
While the forces of battle are arrayed under the banners All-Suffi- 
ciency of Natural Selection and Inheritance of Acquired Modifica- 
tions, there are non-militant biological agriculturalists who till the 
fields of observation and assert that they in truth provide the sinews 
of war. It is to them that we must look for conclusive evidence 
one way or the other. 
We cannot part with Mr Spencer (only for a time it is hoped) 
without again expressing sincere admiration for his genius and 
gratitude for his self-sacrificing labours. C. Lioyp MorGay. 
UNIVERSITY COLLEGE, BRISTOL. 
