. Outlines of zoology. omposed of several phalanges. The hind limb—from Amphibians onwards—consistsof a femur articulating with the girdle, a lower leg com-posed of a tibia and fibula lying side by side, an ankle region or tarsus of several elements, a foot with metatarsalbones in the sole, and with toes composed of severalphalanges. In Fishes the limbs are fins, i.e. without digits. Distinct from the other bones are a few little sesamoidsof occasional occurrence, e.g. the knee-pan or patella. Theydevelop in connection with the tendons of muscles. Nervous system.—This includes—(a) the central Stock Photo
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