158 REPTILES AND BIRDS. 
countries where they are common, and attain size, their flesh is univer- 
sally used for food, and their carapace employed as a canoe. The 
natives even roof their huts with them ; convert them into drinking- 
troughs for their cattle and into baths for their children. According 
to Strabo and Pliny, the ancient inhabitants of the shores of the 
Indian Ocean and the Red Sea converted the Turtle’s carapace 
into similar uses. The fat of many species, when fresh, is used as 
Fig. 38.—Green Turtle. 
a substitute for oil and butter, except when pervaded by a musk-like 
odour, when it is employed in embrocations, in tanning leather, or 
in lamps. The eggs of nearly all the Turtles are valuable as human 
food. Finally, the carapace of several species constitutes a valuable 
material much employed in the arts, and known as tortoise-shell. 
This is sought after in consequence of its hardness, the fine polish 
it is susceptible of receiving, and also for the facility with which it 
is worked. It has a strong resemblance to horn, but is easily dis- 
tinguished from it. It is formed of parallel fibres, and seems to 
be the result of the exudation of solidified mucus. Its texture is 
