228 THE LIVING ANIMALS OF THE WORLD 
Venomous Snakes. The poison-weapons are a spine on the gill-cover and two spines of the 
back-fin. The former is of the same shape as the hollow venom-fang of a snake, perforated 
at both ends. A little bag containing the poison lies at the base of the spine, and when 
pressed by the spine as it makes its puncture ejects its contents into the body of the latter, 
whence it escapes from the hole in the top. The structure of the back-spines is similar. 
The family of the Angler-FISMES contain more strange forms than any other. Living 
on the sea-bottom and seeking their prey by stealth, angler-fishes do not need powerful 
swimming-muscles; consequently the size of the body and tail has become considerably 
reduced, so that the head, relatively to the rest of the body, is unusually large. The head, 
jaws, and belly are indeed of great size and capacity. The side or paired fins are not 
used for swimming, but have become modified to serve as feet, enabling the fish to shuffle 
along the ground. A further remarkable feature of these fishes is seen in the back-fin, 
the rays of which are very long, the foremost being provided with a flag-like flap of skin at 
Photo by Peinhold T'hUle ^ Co.] [^Chancery Lane^ C. 
ANGLER-FISH 
This hideous species is also called the Frog-fish 
the top, extremely sensitive to touch, and playing a very important part in the capture of 
food. It seems that the fish commonly lies concealed on the sea-bottom, with this “ flag ” 
erected. From its general resemblance to the surrounding seaweed it is quite inconspicuous, 
so that passing fishes take no trouble to avoid it. If by any chance they should touch it, 
however, the jaws beneath open instantly, and the unfortunate trespasser is suddenly engulfed. 
This elaborate and sensitive mechanism has been likened to a spring-trap, which is always set, 
and never betrays its presence. It seems probable, however, that this flag serves also as a lure, 
passing fishes being occasionally attracted by the waving flap of skin. Should they become 
sufficiently curious as to proceed to touch it, capture in the manner above described is certain. 
Certain deep-sea forms have a luminous organ in the place of the flap of skin, and this 
certainly seems to act only as a lure. 
Angler-fishes are found all over the world ; some, as we have seen, are bottom-fishes, some 
inhabit deep sea, whilst others lie hidden amongst floating seaweed, to which they cling by 
