220 FOOT-NOTES TO EVOLUTION. 
and meaningless. We know no facts which lie beyond 
the realm of law. I may close with the language of 
Asa Gray: 
“When we gather into one line the several threads 
of evidence of this sort to which we have here barely 
alluded we find that they lead in the same direction 
with the views furnished by [other lines of investigation]. 
Slender indeed each thread may be, but they are mani- 
fold, and together they bind us firmly to the doctrine of 
the derivation of the species.” 
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