Like many another distinguished gardener, Mr Arnott is a Scotsman, being a native of Dumfries, and now living in the adjoining county of Kirkcudbright. For the last fourteen years his name has been a familiar one to readers of the leading journals devoted to gardening, for he has been a very frequent contributor to The Gardener's Chronicle, The Gardener's Magazine, The Garden, The Journal of Horticulture, and other papers. Although not a professional gardener, Mr Arnott is a practical one, for he manages at least the flower department of his beautiful garden almost without assistance; and having spent most of his life amongst flowers – his mother being a great gardener – he is a successful plant grower, as well as an interested one.
Mr Arnott takes an active part in the work of encouraging the gardening spirit among his countrymen, and is a member of the Scientific Committee of the Royal Caledonian Horticultural Society, as well as a member of other leading associations with similar aims.
CONCERNING BULBS BY THE EDITOR
Anyone who has observed ever so casually the order of flowering of the plants in garden or hedgerow, must have noticed that bulbous plants figure prominently amongst those which flower in the early months of the year. Winter Aconite, Snowdrop, Crocus, Scilla, Chionodoxa, Daffodil, Fritillary, Anemone, and Tulip are among the greatest treasures of the spring garden, and though these are not all strictly bulbous plants, they all have either bulbous, tuberous, or other enlarged form of root or underground stem which serves a like purpose. Even those early flowers, the primroses, are borne on plants whose thick, fleshy, underground parts are almost tuberous in appearance; and it will be found that all the earliest blooming plants of spring are furnished with large stores of nutriment in root or stem. Only by virtue of these granaries of materialised solar energy, accumulated during the spring and summer of the previous year, are plants able to manufacture leaves and beautiful flowers in those early months during which the sun yields little heat and light, so essential to healthy plant life.
In a sense, we may consider bulbs and tubers as functionally equivalent to seeds, for they contain within sundry wrappings a dormant plant and stores of food material, wherewith the young plant may be nourished from the time when growth commences until the plant can fend for itself.
It is easy to understand how great an advantage it may be to a plant, in which cross-fertilisation is essential to racial vigour, to open its flowers before the great armies of floral rivals expose their baits to the gaze of flying insects whose visits are desired. For a like reason, it is advantageous to certain flowers to appear late in autumn after the summer flowers have withered and the competition for insect visitors has abated. These also have usually woody stems, or bulbous or tuberous rhizomes or roots, in which are stored reserves of starch, sugar, and other foods formed in the season of sunlight. Fibrous-rooted plants, on the other hand, for the most part flower between the months of April and September, when the daily hours of sunlight are many.
We commonly speak of the bulbs of crocuses as of tulips or of onions, but morphologically there is a distinction, although functionally there is little or none. If we examine a tulip bulb, we find that it is mainly composed of thick succulent scales which closely overlap one another, in the centre being a flattish axis continuous with the roots below, and with the leaf and flower-bearing stalk above. This axis is part of the tulip's stem, the fleshy scales being morphologically but modified leaves whose basal portions have become swollen with stores of nutriment. After the tulip has flowered, it sets to work to manufacture fresh supplies of food material which is sent down the stem and there accumulated in a new bulb, formed by the development of a bud contained among the scales of the old and now withered bulb of the previous year. These stores will, in the following season, enable the tulip to cut a pretty figure before it or other plant has had time or opportunity for preparing fresh supplies by the aid of the spring-time sun alone.
The so-called bulb of the crocus has a somewhat different structure. The crocus "bulb" does not, like that of the tulip, consist of overlapping scales, but of a more or less homogeneous mass enclosed in a stiff membrane, within which may sometimes be seen two or three smaller membranes of similar structure. From the lower part of the "bulb" issue roots, and from its summit proceed the leaf-bearing and flower-bearing shoots. The crocus "bulb" is not strictly what botanists call a bulb, but is a corm (Κορμος = a stem), the expansion being composed of the swollen base of the stem and not, as with true bulbs, of the leaves – the latter having degenerated into mere membranous sheaths, which have no function beyond serving as protective envelopes for the food store and living nucleus within. As in the case of the tulip, so the crocus, having flowered in the early days of the year, proceeds to make and store up fresh supplies of starch and other food in readiness for the following year. The base of the stem enlarges above the old and withering corm, from which it sucks the remaining nutriment. Fresh roots are formed, some of which, having penetrated the soil to a varying depth, contract in length, and so draw down the new corm to the level of the old.
