flexible; it can turn and twist easily in the water.""Yes, but how does the fish move along?" asked Norah. "It has neither legs nor wings. It has no limbs of any sort.""That"s just what I am coining to next," said Fred. "If you look at a herring you will see several pairs of fins. First there is a pair, one on each breast, just behind the gills. These are the breast fins.
"Then there is another pair on the under part of the body-the belly fins. Teacher says these four answer to the four limbs of land animals.
"Besides these there is generally a large fin on theback, and one more under the body near the tail." "But the largest and most important of all is thebroad upright fin at the end of the body. This is the caudal fin or tail fin.""But why is this one the most important, Fred?" asked Norah.
"Well, it is this tail fin that really does the work of moving the fish through the water," said Fred. "The others are useful to balance the body and guide it as it moves."SUMMARY