The second and third propositions were illustrated by examples which have, with good reason, provoked ridicule. Lamarck accounts for the long neck of the giraffe by that organ being continually stretched out to reach the leaves at the tree-tops; for the long tongue of the ant-eater or the woodpecker by these creatures protruding it to get at food in channel or crevice; for the webbed feet of aquatic animals by the outstretching of the membranes between the toes in swimming; and for the erect position of man by the constant efforts of his ape-like ancestors to keep upright. The legless condition of the serpent which, in the legend of the Garden of Eden, is accounted for on moral grounds, is thus explained by Lamarck: "Snakes sprang from reptiles with four extremities, but having taken up the habit of moving along the earth and concealing themselves among bushes, their bodies, owing to repeated efforts to elongate themselves and to pass through narrow spaces, have acquired a considerable length out of all proportion to their width. Since long feet would have been very useless, and short feet would have been incapable of moving their bodies, there resulted a cessation of use of these parts, which has finally caused them to totally disappear, although they were originally part of the plan of organization in these animals." The discovery of an efficient cause of modifications, which Lamarck refers to the efforts of the creatures themselves, has placed his speculations in the museum of biological curiosities; but sharp controversy rages to-day over the question raised in Lamarck's fourth proposition, namely, the transmission of characters acquired by the parent during its lifetime to the offspring. This burning question between Weismann and his opponents, involving the serious problem of heredity, will remain unsettled till a long series of observations supply material for judgment.