112 
ANIMAL CURIOSITIES 
pieces of vegetation, some of which is eaten 
by the crabs, while the remainder rots away 
and forms the nucleus of a new soil. On some 
of the coral islands of the Eastern Archipelago 
the crabs are gradually converting mud-flats 
into dry land, and although the process is 
naturally a slow one, yet owing to the enormous 
numbers of the creatures, as many as one 
hundred burrows sometimes being located 
in an area measuring but two feet square, 
the work proceeds faster than one would 
expect. 
The Keeling or Cocos Islands in the Indian 
Ocean are the homes of some crabs that not 
only pass the greater part of their existence 
upon land, but are also partially arboreal in 
habits, the crustaceans climbing coco-nut 
trees for the purpose of feeding upon the fruit. 
Known as robber crabs or coco-nut crabs, 
these creatures attain to a considerable size, 
a length of a foot or more being by no means 
unusual. They belong to the group of hermit- 
crabs, but differ from the typical forms, in 
which the body is naked and unprotected by 
a shell covering, by having the upper surface 
furnished with horny plates. They make 
their homes in deep burrows which they 
excavate beneath the roots of trees, and 
within the privacy of these sanctums they 
