894 Marvels of the Universe 
On the foreshore 
only a few species are 
found, but, as revealed 
by the voyage of the 
Challenger, these mys- 
terious animals 
abound in the great 
abysses of the ocean, 
often to the extent of 
providing a recognized 
character of the fauna 
over vast areas. Even 
at a depth of two 
miles or more they 
make their home, and 
what is more remark- 
able, the deep-sea 
forms are by no means 
dwarfed by their en- 
vironment ; indeed, 
some of them attain 
a comparatively large 
THE EVOLUTION OF THE LIZARD. 
These five species of Skinks illustrate the gradual reduction and disappearance of the limbs 
size, as, for example, 
and the transition from a lizard-like to a snake-like bodily form. pixom the topmost specimen, the Mighty Sea-spider 
which has both pairs of limbs present, each with five toes, and with the tail distinct from the 
body, it passes through an evolution by gradual stages till in the last the limbs are reduced to Of the Southern Ocean, 
minute undivided vestiges and the bodily form is snake-like. which is illustrated on 
page 8o1, can extend its legs to cover nearly two feet of space. These deep-sea forms are usually 
of an orange or bright red colour ; the example Nymphon, which appears amongst the illustra- 
tions (page 890), is also a denizen of the ocean depths. Another feature worthy of note regarding 
these deep-water species is that their eyes are often imperfect, being destitute of both lens and 
pigment. In one species which was dredged by the Challenger at a depth of only thirty-eight 
fathoms, eyes were found to be lacking. On the other hand, many species dredged from a depth of 
over two miles have their eyes normally developed. 
The male takes the ball of eggs from the female and may carry several masses, each one repre- 
senting the whole brood of one female. The eggs of the various species differ considerably in size, 
some masses containing more than a hundred, while those of the small members of the genus Pallene 
are so large that there are usually not more than two eggs in each mass. When the larve 
hatch out, they cling to the body of their parent, who carries them about until they can take care 
of themselves. The young, unlike spiders, undergo a true metamorphosis before completing their 
development. 
THE EVOLUTION OR EE GEESSREIZNKDS 
BY W. P. PYCRAFT, A.L.S., F.Z.S., ETC. 
THAT animals may undergo profound transformations of shape in respoase to the demands of a new 
environment is an undoubted fact, though the process of change is so slight as to be imperceptible, 
even in a hundred generations. But there are some curious exceptions to the rule. Thus aquatic 
animals reveal their habitat by their feet, which are commonly webbed. Often the whole leg under- 
goes transformation. In the seals, for example, the limbs are little more than flippers ; but those 
