This section is from the book "The Gardener's Monthly And Horticulturist V21", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
In looking over my collection of drawings of such objects of interest as have come to my notice from time to time, while investigating vegetable physiology, I have concluded to copy some relating to the growth of the Potato. I herewith send you five illustrations to begin with, which may interest some of your readers should the drawing be worthy or fitted for an electrotype of a reduced size, and the subject matter suitable for your valuable Monthly if not, let it go into your waste basket among ot her trash.
Fig. 1, is one of several brought to my notice where the stoloniferous or underground stems of a species of grass (Muhlenbergia) was found embedded in a tuber, by Mrs. P. E. Gibbons, October 29, 1870. Fig. 2, showing the tuber of an Artichoke, Helianthus tuberosus L., was embed-ded in another from J. S.Witmer, of Paradise, Lancaster Co., Pa., Febuary 22, 1873. Fig. 3, a twisted iron-link of a chain partially embedded, from H. L. Eckert, Lancaster, March 27, 1875. These three productions show that the cellular action of growth in the Potato surrounds the object with which it comes in contact. Figs. 4 and 5, present a different phase of an internal bud or eye, giving rise to new tubers. Fig. 4, was a fine Early Hose Potato, externally smooth, showing two young tubers growing within the parent, from J. Hartman Hershey, among other potatoes exhibited. Fig. 5, a Mercer Potato, greatly wrinkled and withered externally, showing three young tubers and roots issuing from the interior of the old tuber. This or these freaks may be common and perhaps by no means strange to most of your readers; nevertheless, I find no mention or explanation of the phenomena, if such it may be called. Mr. Geo. 0. Hensel, also brought me the bulb of a Tulip, which embedded a rhizoma of a •species of grass.
The structure of the tuber and bulb being in some respects different, yet no doubt the same law governs both cases. We frequently notice the late or prostrate potato vines beset with young tubers mixed with fresh foliage.
POTATO GROWTH EXTRA.
In Blyth's copy of "Liebig's Natural Laws of Husbandry," I find it stated that a potato, which lay wrapt up in thick paper, in a box, in the chemical labratory at Giessen, in a place absolutely dark, dry and warm, where the atmosphere was seldom changed, was found to have produced from each bud, a simple white shoot many feet long, showing no traces of leaves, but covered with hundreds of minute potatoes, which exhibited the same internal structure as tubers grown in a field; the cells consisted of cellulose, and were filled with minute starch granules. It is certain that the starch of the mother tuber, to have moved away from its position, must have become soluble; but it is equally clear, that in the development of the shoots, a cause was operative within them, which, in the absence of all outward causes whereon growth depends, reconverted the dissolved constituents of the mother tuber into cellulose and starch granules. I shall make no comment upon the foregoing, only that the tuber contains within its own substance the elements required to form the organs which are in-| tended to take up food from the air and soil; in the foregoing case however, no soil is present, which makes it more marvellous.
It is not my object to enter upon a learned disquisition on cellular tissues, which assume a great variety of forms, varying with the circumstances in which it is placed.
The parenchymous tissue is in general the depository of all the materials which in vegetables administer to the sustenance of man. It is here we find deposited the material that forms our bread, from whatever grain or source derived, or may be manufactured. It is the cellular tissue filled with an amylaceous substance that composes the edible part of the roots that are brought to our tables. The mealiness of potatoes, as we call it, is but the swollen starch grains which compose this important vegetable.
We will now consider the multiplication of cells of young tubers coming in contact with a fixed root or object in the soil; this cell formation will proceed in the direction of the least resistance, the plastic condition by a kind of involution of the mother cell and extension laterally, the cells will continue to form, as in the ordinary process of development, until the object is encompassed (if not too large) and embedded among the tissues. This simple natural process accounts for the three cases, Figs. 1, 2, and 3. We meet with numerous interruptions of a uniform development in the roots of plants and trees flattened or turned aside by rocks or other obstructions. I mention this, because from the known force of plants under germination exerting a great power, it was supposed that in the case of grass roots, they had penetrated or actually grown into the potato, and such was the opinion of not a few when the first specimen was discussed; but the finding of the iron-link subsequently embedded in a tuber, demanded some other explanation.
I can find no account of the growth of young-Potatoes within the mother tuber, such as Figs. 4 and 5, yet it can not be a rare occurrence. Having met with other cases of the kind, I fancy it may be too common to give it public notice, or how is it? That the eye is the germ, and that it may find a stimulus from within to start it internally as well as to throw out a fiber or tube with bulb-lets upon it externally? This internal starting would be fed and augmented, causing the young tubers to enlarge and burst the walls of the parent, and result in the formation shown.
It is well to notice these deviations from the normal growth, since hints may be imparted to some wide-awake genius, who may get at a truth that might be of service. Should any of your readers have comments to make, I shall be happy to hear from them.