well as nearly complete sets of our then cultivated varieties, pure or hybrid, from four of our largest living collections, and thus acquired a tolerable idea of the characteristic features assumed by hybrids in this genus. Yet among the wild plants there was only one, in an old collection of Roxburgh's, that had the slightest appearance of a hybrid; and among European ones, the only instance I am aware of, is that mentioned by Hewett Watson, of the Cornish hybrids, between E. ciliaris and E. Tetralix. So in the genus Dianthus, according to C. P. Gaertner, artificial hybrids are very readily produced, and are more fertile than those of almost any other plants, and yet wild hybrids are very rare. Lecoq, it is true, speaks of hybrids between D. Monspessulasnus and D. Seguieri as being very abundant in the Montdore, and certainly these two species are, in that locality, very variable, but not more so than I have observed them in the Pyrenees, Provence, &c., when growing separately.
The apparent permanence given by cultivation to abnormal or intermediate races has afforded a plausible argument against the supposed constancy of the limits assigned to species in nature. The manner in which the Cape Pelargoniums, the South American Verbenas and Petunias, &c., have produced varieties without end, blending the original species together in inextricable confusion, is well known; and gardeners reckon with tolerable certainty on reproducing, by seed, the numerous varieties of our kitchen-garden annuals. But, as in the case of artificial hybrids, these plants are then placed in an anomalous condition, in which they are maintained by cultivation only. Restore them to the conditions of a wild growth, leave them exposed to all those obstacles which nature opposes to their multiplication, and they will soon yield to the more hardy or more favoured genuine forms, and gradually perish without being reproduced. This temporary character, when wild, may be observed in all the extraordinary aberrations from the common form, however healthy the individuals may appear, such as Orchis pyramidalis with spurless flowers, or Linaria vulgaris, with five spurs; Helianthemum vulgare, or Narcissus juncifolius, with linear or divided petals; or Stellaria Holostea, with no petals at all, &c.; they are none of them perpetuated; they cannot resist the immense chances there always are against the offspring of any one individual plant ever coming to perfection.[1]
To sum up the foregoing remarks:—When a plant is observed apparently allied to some known species, but differing in one or more characters hitherto unobserved or unrecorded in that species, before deciding
- ↑ As a familiar instance of the disproportionate chances against the success of any individual seed in a wild plant, take the foxglove (Digitalis purpurea). It will often ripen 200 capsules, and even above twice that number have been counted on one plant, and the number of good seeds I have found in one capsule have varied from 800 to 1200. Taking, however, the average number of good seeds shed by every plant as only 100,000; as the average number of foxgloves in a given district remains the same year after year and century after century, we have only one plant coming to perfection
