Page:Popular Science Monthly Volume 67.djvu/344

338 crossed with the large flowered, brilliant orange-red, perennial poppy, and a great number of hybrids were now growing. These were almost all sterile. Some of them terminated in a dried-up stub without flowers, others had a minute rudiment of fruit, others only remnants of calyx and corolla. There were all stages up to normal flowers, and seed capsules in which the not yet fully developed seeds could be seen through a lens.

After crossing all kinds of color varieties of the common poppy he got one with a light blue color. Although the color is not very pretty, yet this plant is very interesting, as blue poppies have been hitherto unknown. Probably the change in color is caused by the combination of pigments in some flowers and the chemical constituents of cells of others. This is, however, only a supposition.

Many other wild plants, as Brodiœas, Erysimums and Cephalyptrum Drummondi, he had hybridized, getting flowers which first came out carmine red, but then slowly changed to white, a very unusual mode of variation. In order to reduce the price of Amaryllis and Gladiolus to a few cents, and thus make these beautiful red and white-striped flowers common in every garden, he devoted attention to the increase of side-bulbs. He had already plants with twenty to twenty-four bulbs instead of the old forms with hardly any or but a few side-bulbs. Burbank has his own peculiar ideas about the power of nature and natural phenomena, which play such an important part in his work. His principal theory is that 'heredity is the sum of all past environments'. This he repeated time and again in his explanations. Crossing brings together in one individual the sum total of the environmental influences to which the two lines of parents have been subjected, and hence increases its variability.

Among the remarkable results of Burbank's work which we saw at the Sebastopol farm were a couple of trees of Loquat (Eryobotrya japonica) about six feet high, but with spreading fruit-laden branches. One of these trees was the original Japanese kind with small yellow fruit, the size of a cherry, of acid taste and almost filled with the large seed. It has a peculiar flavor, found in no other fruit. This aroma was also found in the fruits of the other tree, but these were larger than walnuts and had an orange-red color. The seed was not larger than that of the wild tree, but the juicy fruit-flesh was greatly developed in thickness and very delicious. This improvement of the loquat, which fruit makes one of the finest delicacies for the table, was accomplished by Burbank without crossing, by selection only. This is the same process by which, since the time of the celebrated Belgian