A. Fore-limb of Monkey B. Fore-limb of Whale
What is meant by homology? Essential similarity of architecture, though the appearances may be very different
This is seen in comparing these two fore-limbs, A, of Monkey, B, of Whale. They are as different as possible, yet they show the same bones, e.g. SC, the scapula or shoulder-blade; H, the humerus or upper arm; R and U, the radius and ulna of the fore-arm; CA, the wrist; MC, the palm; and then the fingers.