84 Darwin, and after Darwin. 
these muscles persist, and are then described by 
anatomists as abnormalities. The following illustra- 
tions serve to show the muscles in question, when thus 
found in adult man. 
: Supra-shin 
CURYATORES Coccyc!s bis: 
Fic. 17.—Front and back view of adult human sacrum, showing 
abnormal persistence of vestigial tail-muscles. (The first drawing is 
copied from Prof. Watson’s paper in Journl. Anat. and Phystiol., vol. 
79: the second is compiled from different specimens.) 
(6) Vermiform Appendix of the Cacum—tThis is of 
large size and functional use in the process of digestion 
among many herbivorous animals; while in man it is 
not only too small to serve any such purpose, but is 
even a source of danger to life—many persons dying 
every year from inflammation set up by the lodge- 
ment in this blind tube of fruit-stones, &c. 
In the orang it is longer than in man (Fig. 18), as 
