186 FOREST AND STREAM April, 1920 
THE LIFE HISTORIES OF TURTLES 
A REVIEW OF DR. HAROLD L. BABCOCK’S EXCELLENT MONOGRAPH ON THE TURTLES 
OF NEW ENGLAND. IN WHICH SOME INTERESTING FACTS ARE BROUGHT TO LIGHT 
D R. BABCOCK’S monograph (“The 
Turtles of New England,” issued 
in April, 1919, as a memoir of the 
Boston Society of Natural History treats 
of the seventeen species of chelonians 
that have been recorded from New Eng- 
land. The list includes practically all 
the turtles likely to be encountered in 
northeastern North America, and the au- 
thor’s well-incorporated compilations 
from a wide range of literature, ancient 
and medieval as well as modern, present 
much general information which will be 
no less valuable to naturalists in Japan 
or Great Britain than to persons inter- 
ested in the turtles of our own country. 
Four of the New England turtles are 
marine species; one (the diamond-back 
terrapin) is confined to littoral waters; 
one (the box tortoise) is almost entirely 
terrestrial; the remainder are stream or 
pond turtles, except that the wood tor- 
toise, Blanding’s tortoise, and one or two 
others have more or less strongly devel- 
oped terrestrial proclivities, and in hab- 
its and appearance are somewhat inter- 
mediate between water and land turtles. 
Most of the freshwater species are also 
likely to occur in salt or brackish 
marshes. 
In his introduction, Dr. Babcock calls at- 
tention to the fact that turtles have rela- 
tively few natural enemies, among which 
are alligators and crocodiles, sharks 
and certain large freshwater fishes, pre- 
daceous mammals which eat the eggs, 
certain hawks which sometimes carry off 
adult turtles, bot-flies which lay their 
eggs in the flesh of living animals, and 
intestinal parasites. It is worth men- 
tioning that instances of large sea tur- 
tles being devoured by sharks are cited in 
this department of the July Forest and 
Stream. The great enemy, however, .is 
man. Turtles are useful as a source of 
food, oil, fertilizer, tortoise shell, and 
the utensils or ornaments of primitive 
peoples, and the numbers directly or in- 
directly killed in many parts of the world 
are staggering. Dr. Babcock quotes 
Bates, the author of “The Naturalist on 
the River Amazons” (1863), to show that 
in his time 48,000,000 turtle eggs, or the 
offspring of 400,000 adult females, were 
annually destroyed for the oil of their 
yolks by the natives of the upper Ama- 
zon alone. 
T HE principal external peculiarity of 
turtles — the “shell” — is composed of 
bony plates connecting the flattened 
ribs, and is covered in most cases with 
By ROBERT CUSHMAN MURPHY 
horny scales. The leather-back turtle has 
no external shell, but its loss is believed 
to be a secondary, adaptive modification; 
in other words it is probable that the an- 
cestors of the leather-back were hard- 
shelled turtles. The plastron, or ventral 
portion of the turtle’s armor, is in some 
forms united by immovable bony bridges 
with the carapace; other species have 
only a ligamentary attachment, and the 
plastron itself may be a rigid plate or 
may be hinged transversely so that the 
creature may retire completely into a 
After a colored drawing by R. Deckert. 
Diamond-back terrapin 
tightly closed “box.” One Old World 
turtle has a hinge in the carapace as well 
as in the plastron. A peculiar effect of 
the s'hell is to prevent the usual verte- 
brate method of respiration by muscular 
expansion of the thorax. Since the ribs 
are immovable, the turtle must perforce 
“swallow” the air it breathes, or pump it 
into the lungs by movements of the neck 
and limbs. Respiration in the water is 
supplemented in certain species by mucus 
membrane modifications in the pharynx 
or in the anal region which absorb oxy- 
gen from the water and thus function 
like the gills of fishes. 
Turtles, according to Dr. Babcock, are 
the highest in “psychological develop- 
ment” of existing reptiles. Their brains, 
however, are small and simple when com- 
pared with those of even the most primi- 
tive mammals and birds, and the large- 
headedness of many species, such as the 
loggerhead, is due to a secondary bony 
roof over the insertions of huge mus- 
cles that are attached to the skull. One 
would have to cut deeply through flesh 
and bone to fine in the center of the head 
the tiny capsule encasing the brain. Tur- 
tles attain great age. “Gilbert White’s 
famous tortoise ( Testudo ibera) lived 
nearly sixty years. A giant tortoise 
( T . sumerrei) was in captivity at Port 
Louis when the island of Mauritius be- 
came a British possession in 1810. It 
was still alive in 1909, although nearly 
blind, being kept in the grounds of the 
barracks of the garrison. Undoubtedly 
some of the giant land tortoises of the 
Galapagos and Aldabra islands are the 
oldest living animals on earth.” There 
is, of course, little exact data on this 
subject, and it may be suggested that 
elephants, crocodiles, or even eagles, 
might have as good a claim to maximum 
longevity as Dr. Babcock’s favorites. The 
author wisely adds to his discussion, “De- 
termining the age of turtles from dates 
previously cut in their shells may be very 
misleading.” 
Regarding the astonishing vitality of 
turtles, Dr. Babcock writes: “Specimens 
have been kept alive for a year without 
food or water; others have been frozen 
solid in ice, thawed out, and still 'Sur- 
vived.” He also refers to other examples 
of the tenacity of life processes, such as 
the continued snapping and clamping of 
the jaws after the head of a turtle had 
been severed from its body, but he makes 
no mention of the persistent contractile 
power of the chelonian heart. Hadley 
(Science, XLIV, 1916, p. 312) records 
that he removed the heart of snapping 
turtle and placed it in a vessel contain- 
ing normal salt solution, whereupon it 
continued to beat at a slightly increasing 
rate for about six hours. 
O F the four sea turtles reaching New 
England, the largest is the leather- 
back, for which no less than thirty 
records are cited. This species sometimes 
reached a length of seven feet and a 
weight of 1,500 lbs., so that it can be 
compared only with its still more gigantic 
fossil relatives. Frequently in summer 
examples migrate northward in the Gulf 
Stream, and then turn into the colder 
