356 THE POPULAR SCIENCE MONTHLY 
THE NATURAL HISTORY AND PHYSIOLOGY OF 
HIBERNATION 
By ALLEN CLEGHORN, M.D. 
LATE INSTRUCTOR IN COMPARATIVE PHYSIOLOGY, LATE ASSISTANT IN PRACTICAL 
PHYSIOLOGY, HARVARD VETERINARY AND MEDICAL SCHOOLS 
INTRODUCTION—NATURAL HISTORY 
ie this most important and interesting phenomenon of nature—a 
truly protective phase—let us first briefly consider the natural-his- 
tory side of the subject, describing how hibernation is peculiar to, and 
differs, in the various animals possessing this function of protective 
winter sleep. Then we will consider the various physiological phe- 
nomena characteristic of this torpid state. Let us first make clear the 
meaning of some of the terms used in connection with this condition. 
The term “hibernation” is used by scientists and naturalists to 
signify the peculiar somnolent or torpid state in which many animals, 
both warm- and cold-blooded, inhabiting cold and temperate climes, 
pass the winter. On the other hand, in hot and dry countries, various 
animals pass into a similar condition during the hottest and dryest 
season of the year, and this state is called “ estivation.” 
Many of the animals which hibernate during the winter are liable 
to fall into a similar state at intervals during milder seasons—Dr. 
Marshall Hall considers the day sleep of bats as a species of hiberna- 
tion and has called it “ diurnation.” 
In man it is a question if true hibernation ever occurs—a similar 
condition may exist, however, but it is very rare either for a prolonged 
or short period. Cases of hibernation (?) in man are most frequently 
found in India, where some religious ascetics are stated, upon unim- 
peachable authority to possess the power of throwing themselves into a 
state closely resembling hibernation (trance?) for an indefinite period. 
Many curious cases have been recorded by Mr. Braid in his treatise on 
“ Human Hibernation ”; the most celebrated and best known is that of 
a “fakir,’ who, in the presence of Sir Claude Wade, the English gov- 
ernor, was buried alive at Lahore in 1837, was exhumed and restored to 
consciousness after remaining in the ground for several months, the 
grave being guarded and every precaution taken, in the meantime, to 
prevent any interference or disturbance of the body. 
One of the largest groups of hibernating animals we have is that 
of bats—Dr. Marshall Hall claims that the bat when hibernating, prac- 
tically never wakes, but when disturbed will breathe naturally,’ for a 
few minutes, but will then return to its former state of quiescence. 
17. e., as in a fully wakened state, quicker and deeper. 
