882 Marvels of the Universe 
CRAB DEVELOPMENT. 
These figures show successive stages in the early life of the 
common Shore-crab. The third and fourth show the same infant 
Crab from above and from the side respectively. 
‘that it was not in the habit of burrowing, or of 
seeking food underground. In this particular 
form (Glyptodon asper) the bony scutis of the 
carapace has a beautiful rosette-like sculpture, 
while the sheath of the tail is entirely com- 
posed of a series of movable rings, ornamented 
with large projecting tubercles ; the vertebre 
of the backbone are almost entirely fused 
together into a long tube, and also are joined 
to the under-surface of the great shield, to 
which the ribs are united. The cheek-teeth 
are sixteen in number, four above and four 
below on each side. These are channelled with 
two broad and deep grooves, which divide the 
surface into three distinct lobes. | Hence the 
name of the animal. The anatomy of this 
armadillo greatly resembles that of a giant 
sloth. In fact, sloths, ant-eaters, and arma- 
dillos all belong to the same family of so-called 
toothless animals with no front teeth, though 
one or two forms are really toothless. Their 
diet was vegetarian, but we do not know much 
about their habits. One would think they 
had but few enemies, being quite safe from 
snakes. Monkeys also could not hurt them. 
But why they died out is a mystery. Were 
they too big? or did the little modern 
armadillo beat them in brain-power? We 
cannot tell. Possibly man was the extermina- 
ting agent. 
THE TRANSFORMATIONS OF 
CRABS 
Amonc the important secrets of Nature which 
were reserved for the naturalists of the last 
century to reveal was the fact that all animals, 
other than the most primitive forms, pass 
through a series of metamorphoses before they 
arrive at their final adult state. The ancient 
philosophers knew the fact concerning the 
evolution of the bright and airy butterfly 
from a ‘“ grovelling worm,” the caterpillar ; 
but the truth that fishes and crustaceans pass 
through similar states of incompleteness was 
not dreamt of until comparatively recently. 
It is true that nearly a hundred and fifty years 
ago, the Dutch naturalist Slabber declared that 
he saw a minute marine creature known as a 
