15 



odours, and secrete no mellifluous nectar. Their inconspicuous blossoms, 

 which would scarcely be recognised as flowers at all, for they never expand 

 to the sun's rays, or flaunt banners of brilliant dye to tempt the roving bee 

 or erratic moth. The whole energy of the blossom is devoted to the produc- 

 tion of seeds, a stamen or two evolves a few grains of pollen side by side 

 with the receptive stigmas, which are thereby fecundated with the least 

 possible expenditure of force, numerous seeds being the result. Such flowers 

 are called cleistogamic, meaning a hidden or concealed marriage, and they 

 occur in a few plants, such as violets, wood sorrel, dead nettle, &c. It is a 

 curious fact that these plants produce showy, conspicuous flowers, evidently 

 adapted for insect visits, and yet they are rarely fertile, for which these latter 

 seeds bearing flowers seem a compensation. But of all we know of the 

 beneficial effects of cross-fertilisation, it is more than likely that an occasional 

 cross to infuse fresh vigour into the offspring does occur by means of these 

 blossoms. 



In this connection a reference may be made to the defences of plants, 

 which are most frequently ingenious barriers to repel intruders, who would 

 rob the flowers of their stores of nectar without affording any compensatory 

 advantage to the plant. The most pertinacious and predatory of the unwel- 

 come marauders are ants, and such like " crawling ferlies," whose partiality 

 for sweets is notorious. Against these aggressors, the rigid hairs, which so 

 frequently fringe the stem or the outer portions of the hWer, are unscaleable 

 ramparts, aided in many cases by the moat-like receptacle of water in the 

 leaves, as in teasel, or the glutinous exudation which clothes the stems of 

 pinks, &c. Whilst the insatiable caterpillar and omnivorous slugs and 

 snails are kept at bay by these devices of prickles, spines, hairs and gummy 

 excretions. 



HOW PLANTS INCREASE IN SIZE. 



Although the sources of food supply and how they are utilized by the 

 plant has already been indicated, it may still be a mystery to the botanical 

 tyro how the young seedling can continue to grow and add continuously to 

 its bulk, the sapling become a tree and the tree retain its majestic form, 

 unimpaired for centuries. A noble tree is the largest of all living things, 

 rivalled only by the leviathan of the seas in weight of carcase, but unsurpassed 

 in size in the corner of the universe which it fills, and certainly 

 unapproachable in its duration in the cycles of time. How these mammoth 

 monarch s of the forest have been evolved from the tiny seed, and by what 

 gradual accretions of atoms they have obtained their ponderous proportions 



