322. Diagram of the same phenomenon in a ram’s horn . . . 623 323. Antlers of a Swedish elk (Lönnberg) . . . 629 324. Head and antlers of _Cervus duvauceli_ (Lydekker) . . . 630 325, 6. Diagrams of spiral phyllotaxis (P. G. Tait) . . . 644, 5 327. Further diagrams of phyllotaxis, to shew how various spiral appearances may arise out of one and the same angular leaf-divergence . . . 648 328. Diagrammatic outlines of various sea-urchins . . . 664 329, 30. Diagrams of the angle of branching in blood-vessels (Hess) . . . 667, 8 331, 2. Diagrams illustrating the flexure of a beam . . . 674, 8 333. An example of the mode of arrangement of bast-fibres in a plant-stem (Schwendener) . . . 680 334. Section of the head of a femur, to shew its trabecular structure (Schäfer, after Robinson) . . . 681 335. Comparative diagrams of a crane-head and the head of a femur (Culmann and H. Meyer) . . . 682 336. Diagram of stress-lines in the human foot (Sir D. MacAlister, after H. Meyer) . . . 684 337. Trabecular structure of the _os calcis_ (_do._) . . . 685 338. Diagram of shearing-stress in a loaded pillar . . . 686 339. Diagrams of tied arch, and bowstring girder (Fidler) . . . 693 340, 1. Diagrams of a bridge: shewing proposed span, the corresponding stress-diagram and reciprocal plan of construction (_do._) . . . 696 342. A loaded bracket and its reciprocal construction-diagram (Culmann) . . . 697 343, 4. A cantilever bridge, with its reciprocal diagrams (Fidler) . . . 698 345. A two-armed cantilever of the Forth Bridge (_do._) . . . 700 346. A two-armed cantilever with load distributed over two pier-heads, as in the quadrupedal skeleton . . . 700 347–9. Stress-diagrams. or diagrams of bending moments, in the backbones of the horse, of a Dinosaur, and of _Titanotherium_ . . . 701–4 350. The skeleton of _Stegosaurus_ . . . 707 351. Bending-moments in a beam with fixed ends, to illustrate the mechanics of chevron-bones . . . 709 352, 3. Coordinate diagrams of a circle, and its deformation into an ellipse . . . 729 354. Comparison, by means of Cartesian coordinates, of the cannon-bones of various ruminant animals . . . 729 355, 6. Logarithmic coordinates, and the circle of Fig. 352 inscribed therein . . . 729, 31 357, 8. Diagrams of oblique and radial coordinates . . . 731 359. Lanceolate, ovate and cordate leaves, compared by the help of radial coordinates . . . 732 360. A leaf of _Begonia daedalea_ . . . 733 361. A network of logarithmic spiral coordinates . . . 735 362, 3. Feet of ox, sheep and giraffe, compared by means of Cartesian coordinates . . . 738, 40 364, 6. “Proportional diagrams” of human physiognomy (Albert Dürer) . . . 740, 2 365. Median and lateral toes of a tapir, compared by means of rectangular and oblique coordinates . . . 741 367, 8. A comparison of the copepods _Oithona_ and _Sapphirina_ . . . 742