Evening star., 1932-04-25
SNAKES UTILIZED
FOR FEVER STUDY
Reptiles Show Wide Variation
in Body Temperature.
Zoo Danger Shown.

Experiments with snakes at the Ma
tional Geological Park here may throw
light on. the mechanism of fever in
human beings
These are reported by Dr. Francis
@ Benedict, director of the nutrition
laboratory of the Carnegie Institution
OF Washing, IN, in statement issued
by the institution yesterday. DR.. Bene-
dict has made more than 1000 body
temperature measurements on reptiles
at the Washington and New York Zoos,
some involving the use Of extremely
delicate instruments and considerable
danger for their manipulators.
The reptile, DR.. Benedict explained,
Is especially adapted to study of the
fundamental elements of body tempera-
ture production because its heat varies
almost exactly with the heat of its en-
vironment, and the problem is not
complicated by the extremely intri-
cate mechanism for maintaining a con-
stant body heat which is necessary for
warm-blooded animals.
Needs Little Food.
The body temperature of manuals, he
says, remains essentially constant in
health regardless of what the ther-
mometer may read outside the body.
But, he continues, the cold -blooded
animals temperature and heat produc-
tion increase and decrease with the rise
and fall Of the temperature of the air
around it. During periods of dormaney
or Information its heat production
reaches an almost immeasurably low
level. 1t therefore needs very little food
compared with the warm -blooded
animal.
Yet the large serpents often eat an
enormous meal at one time. During
our study 70-pound python ate 20
pound pig, 400 times its daily energy
need, or enough to last it year. With
no other animals in the world can one
expect such economy in energy expendi-
ture and 1t becomes easy to understand
why it is possible for large snake to
exist year or longer without food.
We found that the mouse, one of the
smallest mammals, produces $40 calories
OF heat for each square meter of its
surface area under normal conditions,
without activity, at a temperature
around it of 80 Farenheit The snake
under the same conditions can produce
at the most only 100 calorieS per square
meter of body surface"
Female Python Studied.
DR.. Benedict found three intermediate
steps between the constantly fiuctuating
temperature of the reptile and the con-
stantly stable temperature of the man.
NAL. One of these was noted in the
study of female python incubating her
eggs at the Washington Zoo Contrary
to her normal condition, this reptile
maintained a body heat of approx
mately degrees above that of the air
OF the cage as long as she remained
coiled around her eggs. The next step
upward was found among the tortoises.
Although they belong clearly within the
great reptile family they have much
higher heat production for each square
meter of surface area than the snakes,
alligatorS or lizards This numbering
creature, he concludes, may be con-
Sidered as an intermediate between the
warm-blooded and the cold-blooded
divisions Of the animal kingdom 1t has
much richer blood supply than the
other reptiles, although it remains far
below the mammals in this respect.
The next stage III this progress, Dr.
Benedict found, was represented by the
alternating animal. During the Winter
sleep, he explains, the warm-blooded
animals vital activity is greatly lowered.
Indeed he continues, "the body tenn
perature of hibernating, warm
blooded animal may easily be the same
do lAAcb VI d SAAdhS, dA1SdOOt VI 11oAAs 4OA
its temperature will fall with that of
its environment nearly down to the
freezing point of water without resulting
in the death of the animal 1t is thus
possible to compare the heat production
of a alternating woodchuck with that
of a lizard of the same body weight and
the same body or cell temperature.
Such study now is in progress. Thus
far results have shown that this animal
even at the same cell temperature as