4 
In its structure, Tortoise Shell is identical with horn, being composed of 
an aggregation of cells filled with horny matter. A vertical section displays 
a laminated structure, whilst in a horizontal one, the cells are seen as they 
approach the surface to become flattened into mere scales. Mingled with 
the horny epidermic cells are others which secrete pigment, and it is to 
these that Tortoise Shell owes its beautifully mottled appearance. Only 
the plates from the carapace of the Turtle are employed in the arts, those of 
the Plastron being useless. There are thirteen principal plates on the 
centre of the carapace, and twenty-five smaller ones which form its rim. 
These last are technically termed " Noses " the larger are designated as 
" Heads." The Hawk's Bill Turtle is an inhabitant of all warm seas, but is 
found principally within the tropics. Our chief supply of Tortoise Shell is 
derived from the numerous Islands of the American and Indian Seas, but 
mainly from that of Ascension. One or two specimens have been known to 
reach our own coasts. In general form the carapace of the Hawk's Bill 
Turtle is flattish heart shaped, in young animals the centre of each scute or 
plate is pointed, but in the adult the points are worn away. The thickness 
of the scutes increases with age, a fresh layer being added every year. The 
most general modes of capturing the Turtle, are either harpooning them out 
at sea, or taking them when they come on shore to deposit their eggs, by 
cutting off their retreat from the water, and turning them on their backs, in 
which state they are helpless. The Chinese use the Remora or Sucking Fish 
in capturing these animals. The Fish are kept in tubs, in a boat, and when 
a Turtle is observed, they are put into the water with a string tied to their 
tails. No sooner does the fish see the Turtle than it darts at it, and adheres 
so firmly to the shell, by means of its sucking apparatus, that both Fish and 
Turtle are drawn into the beat by means of the string. The removal of the 
plates from the carapace of the Turtle is rather a cruel process, the poor 
animals being exposed to a strong heat, which causes the plates to separate 
from the bone. After the plates have been removed the Turtle is set at 
liberty, and it is, after a time, furnished with a new set of plates, but 
inferior in quality and thickness to the old ones. When first removed the 
plates are crimpled, dirty, opaque, brittle, and quite useless for the purposes 
of manufacture. After being boiled and steamed, however, they become 
quite clean and soft, and are easily flattened by pressure, and are then fit for 
artistic purposes. Tortoise Shell possesses the valuable property of being 
easily welded, simply by the application of heat and pressure. Its application 
in the arts is so well known, that I need not dwell upon it here. 
