3 Egg-shaped.

8 Awl-shaped.

5 Oblong. 6 Spear-shaped. 10 Heart-shaped.

4 Oval.
9 Kidney-shaped.

7 Strap-shaped. 11 Crescent-shaped. 12 Triangular. 13 Arrow-shaped. 14 Heart-arrow-shaped. 15 Halberd-shaped. 16 Notched at the end. 17 Three-lobed. 18 Bitten. 19 Gashed. 20 Five-cornered. 21 Gnawed. 22 Hand-shaped. 23 Winged Clefts. 26 Indented and toothed. 30 Toothed.

25 Indented.

27 Barbed.

31 Serrated.

24 Jagged. 28 Divided. 32 Doubly serrated. 36 Sharply 41 Tapering 45 Triangularly 48 Finger-like

29 Serpentine (at the edge).
33 Doubly scolloped. 34 Sharply scolloped. 35 Bluntly scolloped.
notched at the end. 37 Plaited. 38 Scolloped. 39 Blunt. 40 Acute.
to a point. 42 Blunt, but ending in a point. 43 Fringed. 44 Veined.
spear-shaped. 46 Fibrous. 47 Growing by threes upon leaf-stalks.

Form of leaves as

Remarks on form of Leaves. Simple leaves, and the pinnae and pinnules of compound leaves, may be described proportion in either of the methods used above. To say the leaf is al growth. "oval" is to employ a general term; to describe the ratios of the axes is to describe facts seen.

Uniform ratios of growth.

Note. Naming a leaf "oval" is simpler than to describe the proportions of its growth; this method implies fewer acts of thought. If sight of a leaf produces expression by the word "oval" that is one act of thought; to compare the axes is more than one act of thought,-looking at each axis produces two acts of thought. To apply rules of analysis does teach thinking. The general terms, or labels for form, are very useful. Following these lines of giving description we might analyse many descriptions from books.

Duration of leaf determined by its defoliation through intrinsic changes.

38. Leaf, stalk, and a portion of the stem. An articulation is seen at the junction with the stem, which begins to form early in the season and is completed at its close. There is a kind of disintegration of a transverse layer of cells, which cuts off the petiole in a regular line, and leaves a clean scar.

39. Nasturtium plant. Leaves and flowers with buds in various stages of growth. Observe uniform ratios of growth in leaves preserving similarity of form. In flowerbud the ratios of growth of successive wholes alter as development proceeds; at first the sepals enclose the corolla, later action is greater in corolla.

40. Iris flower. The envelope of the flower consists of six parts which in texture and general appearance resemble petals, three of these hang down, and three stand up, forming a sort of canopy over the central parts of the flower. The stamens are three in number; each has a filament or stalk, and a large anther which opens vertically to shed its pollen on the side facing outwards. Just behind each of the three stamens is a style expanded laterally and

looking much like a petal; the stigma is a shelf-like plate passing horizontally across the style just above the anther. No pollen can pass from a stamen to the adjacent stigma.

The adaptation of parts is admirable for conveyance of pollen by a bee, which, standing upon the only landing place, i.e. the recurved portion of the envelope, thrusts its head down below the anther, and on raising it carries off pollen, to be afterwards lodged upon the stigma of the flower which it may visit.

This flower presents no movements of its parts, hence No inthough it is wonderfully adapted for insuring cross-fertili- telligence zation by the movements of bees, it is not said itself to show any intelligence.

without

movement.

41. Two Iris flowers and a bee. We here observe the three objects which it is necessary to see in order that we may fully understand the life history of the flower. We Enlarging enlarge our field of observation.

42. Lamium flower. The corolla is tubular with a platform in front and a canopy overhanging the entrance to the tube. The stamens are four in number, the inner pair being the shorter.

43. Salvia flower. The corolla resembles that of Lamium in general form. The stamens are only two in number, or rather two are minute and rudimentary; in the other pair, the two anther cells instead of being, as usual, close together, are separated by a long connective; moreover, the lower anther cells contain very little pollen. Anthers are ripe before stigma. (See Lubbock.)

field of observation.

Salvia flower shows fertilization with less pollen pro- More duction than in Lamium. Adaptations for action of separate adaptation, less pollen. parts are provided and there is less pollen production. This flower also shows a sequence of time of growth, i.e. protandary. This teaches that capacity of parts to act separately may be a means of lessening labour.

44. Chestnut-inflorescence. It is an indefinite form of inflorescence, the buds opening from the lower part of the axis first, the upper ones being the youngest. The opening of the buds shows a series of acts of growth. Ob

Series of growth.

Attributes

serving an individual flower when open, its parts are seen. The curvature of the different petals varies; the curvatures of the different filaments of the stamens vary, the 10 stamens of the flower are developed in succession, not all together but as a series of acts.

The specimen presents examples at once of many acts of Asynchresis and Imparisynchresis, and Impariasynchresis; and we say it is very beautiful and wonderful, i.e. it stimulates in the brain of the observer the physical expression of admiration.

The specimen will illustrate the need to subdivide the thing observed into parts that can act separately. The times of growth, and the ratios of growth of the separate parts are the essential characters of the specimen.

45. Sunflower. In a sunflower or other composite flower we have a succession of florets placed on a common receptacle; the florets do not develope all together, but those in the outer zones develope first, the successive zones towards the centre developing one after another in centripetal order. If, then, we consider the successive zones of florets as the subjects observed, we have an example of asynchronous growth. The sequents of this asynchronous growth are important to the flower and to the species. The florets are presented in succession to the visits of insects, to whom they are indebted for effecting cross-fertilization. This series of acts is simple, one subject (one zone) only is active at the same time, so that asynchresis is complete. If the observer prefers to consider all the florets composing the flower head as the individual subjects observed, he will find that no combination of subjects in action recurs, so again it is seen that asynchresis is very great.

Remarks. Having observed examples of visible outcomes of growth. of growth, it may be seen that in the descriptions given we speak often of the attributes time and quantity as characters of the acts of growth. Our first purpose is to show the importance of observing the attributes of growth as demonstrated by specimens, and the forces whose action determines those attributes.

The illustrations already given serve to demonstrate the importance of observing the intrinsic attributes of the acts of growth as seen in the specimens resulting from such growth, viz. the time and the quantity of each act.

Specimens showing relations of the Time of Growth, and the importance of noting the Relations of Acts of Growth as to the time of their occurrence.

Examples showing Relations of the Time of Growth.

46. To begin with examples of plant life, the time or order of events is marked as an important element in the following illustrations. In many insect-fertilized flowers cross-fertilization results from an arrangement in the time of development of the organs. Flowers are called proterogynous when the stigmas are protruded and in receptive condition before the anthers have matured their pollen. On the other hand, they are called proterandrous when the anthers mature and discharge their pollen before the stigma of that blossom is receptive of pollen. Scrophularia is a good instance of proterogony in flowers fertilized by bees.

The following description of this flower is given by Professor Asa Gray1: "The flower is irregular, and is approached from the front, the spreading lower lobe being

1 Structural Bolany, p. 220.