GREEN COLOUR OF SLOTH 
covering of long and coarse hair; secondly, the im- 
mensely long and hooked claws, which are two in the 
fore limbs in the case of the two-toed sloth, Cholepus, 
and three in Bradypus. 
It has no fingers to crook to retain its hold upon a 
branch ; nature has already hooked them for it in a per- 
manent fashion. It can only clutch. The long, wiry 
hair droops over its body, and forms an excellent shelter 
against a tropical downpour. As to this hair, it has been 
pointed out that it fadges well with the sloth’s habits. 
Instead of lying in different directions in different regions 
of the body, as is so generally the case with the mam- 
malia, the hair “flows’’ only downwards ; it cannot 
therefore get wet. But a third danger remains besides 
the chance of falling, and of getting a soaking. The 
sloth has tender flesh, and is an appetizing morsel to 
tree-frequenting beasts of prey; and South America 
harbours one of the largest of these, to wit, the jaguar. 
Defenceless as the sloth is against such attacks, nature 
has provided it with the means of apparently circum- 
venting probable foes. It will very possibly be noticed 
in examining carefully the hair of the sloth, that this has 
often a distinctly green colour. Now it was ascertained 
a good many years ago that this green colour was not in 
the least due to an actual green colour of the individual 
hairs, but to the presence within them of minute green 
plants similar to those which colour so vividly the 
weather side of trees, to microscopic algz in fact. This 
gives to the pelage of our sloth a not unstriking likeness 
to lichens, which is borne out by its bunched-up body, 
not unlikeatreestump. There is, in fact, in one sloth at 
least—there are several species of sloth—a mark in the 
middle of the back which suggests a broken end of a 
branch. Thus we see that the wind is tempered to the 
shorn lamb, if, indeed, so very shaggy a creature may 
be used as an illustration of this dictum. 
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