(11/74. 'Gard. Chronicle' 1841 page 814.) The old FORTY-FOLD POTATO, as already stated, is a purple variety; but a plant long cultivated on the same ground produced, not, as in the case above given, a single white eye, but a whole white tuber, which has since been propagated and keeps true. (11/75. Ibid 1857 page 613.) Several cases have been recorded of large portions of whole rows of potatoes slightly changing their character. (11/76. Ibid 1857 page 679. See also Philips 'Hist. of Vegetables' volume 2 page 91 for other and similar accounts.)
Dahlias propagated by tubers under the hot climate of St. Domingo vary much; Sir R. Schomburgk gives the case of the "Butterfly variety," which the second year produced on the same plant "double and single flowers; here white petals edged with maroon; there of a uniform deep maroon." (11/77. 'Journal of Proc. Linn. Soc.' volume 2 Botany page 132.) Mr. Bree also mentions a plant "which bore two different kinds of self-coloured flowers, as well as a third kind which partook of both colours beautifully intermixed." (11/78. Loudon's 'Gardener's Mag.' volume 8 1832 page 94.) Another case is described of a dahlia with purple flowers which bore a white flower streaked with purple. (11/79. 'Gard. Chronicle' 1850 page 536; and 1842 page 729.)
Considering how long and extensively many Bulbous plants have been cultivated, and how numerous are the varieties produced from seed, these plants have not perhaps varied so much by offsets,--that is, by the production of new bulbs,--as might have been expected. With the Hyacinth, however, several instances have been given by M. Carriere. A case also has been recorded of a blue variety which for three successive years gave offsets producing white flowers with a red centre. (11/80. 'Des Jacinthes' etc. Amsterdam 1768 page 122.) Another hyacinth bore (11/81. 'Gardener's Chronicle' 1845 page 212.) on the same truss a perfectly pink and a perfectly blue flower. I have seen a bulb producing at the same time one stalk or truss with fine blue flowers, another with fine red flowers, and a third with blue flowers on one side and red on the other; several of the flowers being also longitudinally striped red and blue.
Mr. John Scott informs me that in 1862 Imatophyllum miniatum, in the Botanic Gardens of Edinburgh, threw up a sucker which differed from the normal form, in the leaves being two-ranked instead of four-ranked. The leaves were also smaller, with the upper surface raised instead of being channelled.
In the propagation of TULIPS, seedlings are raised, called selfs or breeders, which, "consist of one plain colour on a white or yellow bottom. These, being cultivated on a dry and rather poor soil, become broken or variegated and produce new varieties. The time that elapses before they break varies from one to twenty years or more, and sometimes this change never takes place." (11/82. Loudon's 'Encyclopaedia of Gardening' page 1024.) The broken or variegated colours which give value to all tulips are due to bud-variation; for although the Bybloemens and some other kinds have been raised from several distinct breeders, yet all the Baguets are said to have come from a single breeder or seedling. This bud-variation, in accordance with the views of MM. Vilmorin and Verlot (11/83. 'Production des Varietes' 1865 p. 63.) is probably an attempt to revert to that uniform colour which is natural to the species. A tulip, however, which has already become broken, when treated with too strong manure, is liable to flush or lose by a second act of reversion its variegated colours. Some kinds, as Imperatrix Florum, are much more liable than others to flushing; and Mr. Dickson maintains (11/84. 'Gardener's Chronicle' 1841 page 782; 1842 page 55.) that this can no more be accounted for than the variation of any other plant. He believes that English growers, from care in choosing seed from broken flowers instead of from plain flowers, have to a certain extent diminished the tendency in flowers already broken to flushing or secondary reversion.