536 Trans. Acad. Sci. of St. Louis. 
extra-uterine life. Our domestic calf does not ruminate 
while suckling. The mechanism of rumination is set to 
going at once when the nature of the food is changed. If 
merycoles have not so far borne out anatomically the theory 
of atavism, that does not preclude the possibility of 
gradual structural adaptation to the altered functional 
requirements. It must never be lost sight of that all evolu- 
tionary transformations, be they progressive cr revertive in 
nature, are extremely gradual, and that we should not 
measure evolutionary processes with the infinitesimal measure 
of the few thousand years of historical record. We should 
remember that eons of time lay behind us, and that eons are 
to come! 
In conclusion I will say that — atavism or no atavism — 
human rumination, if genuine, is not a pathological entity, 
but a physiological anomaly. It appears anomalous by com- 
parison with the habits of the overwhelming bulk of non- 
ruminating members of the human family. With most mery- 
coles it assumes the form of a perfectly natural process, 
essential to their individual well-being, any interference with 
which is frequently followed by disturbances of a truly 
pathological nature. I frankly confess to sharing fully 
Eugéne Martel’s view, which appears rational in the light of 
many other manifestations of nature’s willing responsiveness 
to use, abuse and disuse. 
The chemical work, in connection with this report, was 
done at the physiological laboratory of the St. Louis Medical 
College. 
I take pleasure in thanking Dr. John Green, of the faculty, 
for the encouragement he has given me by word and deed, 
and which he is always ready to proffer whenever and 
wherever earnest work is being done. 
Issued May 7, 1894. 
