The Descent of Man

een studying the last molar teeth in the different
races of man, and has come to the same
conclusion as that given in my text, viz., that in
the higher or civilised races they are on the
road towards atrophy or elimination.)
With respect to the alimentary canal, I have met
with an account of only a single rudiment, namely
the vermiform appendage of the caecum.
The caecum is a branch or diverticulum of the
intestine, ending in a cul-de-sac, and is extremely
long in many of the lower vegetablefeeding
mammals. In the marsupial koala it is
actually more than thrice as long as the whole
body. (46. Owen, 'Anatomy of Vertebrates,' vol.
iii. pp. 416, 434, 441.) It is sometimes produced
into a long gradually-tapering point, and is
sometimes constricted in parts. It appears as if,
in consequence of changed diet or habits, the
caecum had become much shortened in various
animals, the vermiform appendage being left as
a rudiment of the shortened part. That this ap-