Page:Popular Science Monthly Volume 69.djvu/370

366 success, Burbank has an advantage of true scientific character over his fellow workers, and in it he makes a genuine contribution to scientific knowledge of plant biology, albeit this knowledge is so far only proved to be attainable and to exist. It is not yet exposed in its details and may never be, however unselfish be the owner of it. For the going to oblivion of scientific data of an extent and value equivalent, I may estimate roughly, to those now issuing from any half dozen experimental laboratories of variation and heredity, is the crying regret of all evolution students acquainted with the situation. The recently assumed relations of Mr. Burbank to the Carnegie Institution are our present chief hope for at least a lessening of this loss.

But let us follow our saved plum seedling. Have we now to wait the six or seven years before a plum tree comes into bearing to know by actual seeing and testing what new sort of plum we have? No; and here again is one of Burbank' s contributions (not wholly original to be sure, but original in the extent and perfection of its development) to the scientific aspects of plant-breeding. This saved seedling and other similar saved ones (for from the examination of 20,000 seedlings, say, Burbank will find a few tens or even scores in which he has faith of reward) will be taken from their plots and grafted on to the sturdy branches of some full-grown vigorous plum tree, so that in the next season or second next our seedling stem will bear its flowers and fruits. Here are years saved. Twenty, forty, sixty, different seedlings grafted on to one strong tree (in a particular instance Burbank had 600 plum grafts on a single tree!); and each seedling-stem certain to bear its own kind of leaf and flower and fruit. For we have long known that the scion is not materially influenced by the stock nor the stock by the scion; that is not modified radically, although grafting sometimes increases or otherwise modifies the vigor of growth and the extent of the root system of the stock.

If now the fruit from our variant seedling is sufficiently desirable; if it produces earlier or later, sweeter or larger, firmer or more abundant, plums, we have a new race of plums, a 'new creation' to go into that thin catalogue of results. For by simply subdividing the wood of the new branch, i. e., making new grafts from it, the new plum can be perpetuated and increased at will. Simple, is it not? No, it is anything but that in the reality of doing it; but in the scientific aspects of it, easily understandable.

Perhaps it may not be amiss to call attention to what must be the familiar knowledge of most of us, and that is the fact that many (probably most) cultivated plants must be reproduced by division, that is by cuttings, buds or grafts, and not by seeds, in order to grow 'true.' For a piece of a cultivated plant will grow out to be very much like the individual it was cut from, but the seeds will not, in most