38 
PROOFS OF EVOLUTION. 
reptiles, are all useless rudiments. The crabs and 
fish in the Mammoth Cave have lost their eyes by 
disuse, but the sockets remain as rudimentary 
remnants. But more significant than all these, 
are the proofs furnished by the highest animal — 
Man. In all parts of his bodily structure are found 
the strongest evidences of his animal origin. He 
has dormant scalp and skin muscles, which were of 
great service to his ancestors, but of no use to 
him. Many persons are found who still possess 
the faculty of moving the scalp and ears in a 
remarkable degree, owing, no doubt, to the fact 
that their ancestors have continued the habit. 
Man has a remnant of a third eye-lid, now 
possessed only by some birds and beasts, in the 
crescent-shaped fold next to the nose. The nipples 
and mammary glands of males are wholly useless 
and suggest the differentiation of the two sexes 
from a common parent form. The sparse covering 
of hair on the human body is a lingering reminder 
of a time when clothes were at a discount. Even 
now we see some hairy specimens of humanity 
exhibited as curiosities, which doubtless represent 
a reversion to ancestral conditions. The thyroid 
gland in man is a rudimentary and wholly useless 
organ, which sometimes becomes the seat of 
