6. _Complex adjustments of nature._ Evolution in vain attempts to account for the wonderful complex adjustments we see in nature, such as the mimicry of animals and plants; the walking stick so closely resembles a twig that it deceives the closest observer. The withered leaf butterfly, with spots and wrinkles, is exactly like the thing it imitates. This is true also of the leaf butterfly and of another which exactly resembles a bird's dropping. Evolution cannot account for the ventriloquism of insects, such as the cricket and tree toad; the battery of the electric eel; the beauty of insects and fish and shells and birds and flowers, especially the harmony of their colors. Edible insects are plainly colored, the poisonous kinds highly colored. Some butterflies have "scare-heads" on their wings, exactly resembling an owl's head, and other insects have similar frightful appearances which they thrust out when attacked. All this tells of design and interest and often has the appearance of humor in the creation of these numerous creatures. 7. _The mathematical adjustments of nature are as exact as the multiplication table._ Illustrations of this are the accuracy of the orbits of the heavenly bodies and the law of gravitation. The growth of the cell proceeds on geometrical progression in the division of parts into 2, 4, 8, 16, etc. The climbing plants form their coils with mathematical accuracy and proportion. The proportions in which chemicals will mix is mathematically fixed. Prof. Tyndall thus calls our attention to crystallization: "By permitting alum to crystallize in this slow way we obtain these perfect octahedrons; by allowing carbonate of lime to crystallize, nature produces these beautiful rhomboids; when silica crystallizes we have formed the hexagonal prisms capped at the end by pyramids; by allowing saltpeter to crystallize, we have these prismatic masses, and when carbon crystallizes we have the diamond." (_Fragments of Science_, p. 357.) "Looking at it mentally we see the molecules [of sulphate of soda] like disciplined squadrons under a governing eye, arranging themselves into battalions, gathering around distinct centers and forming themselves into distinct solid masses, which after a time assume the visible shape of the crystal now held in my hand. Here then is an architect at work, who makes no chips nor din, and who is now building the particles into crystals similar in shape to these beautiful masses we see upon the table." (_Belfast Address._)