The simplest case that may be given, is when an ordinary retrograde variety is cultivated with the species to which it belongs. For instance, if dwarfs are cultivated next to the taller type, or a white variety next to the red or blue-flowering species, or thornless forms in neighboring beds with the armed species. Bees and Bumble-bees, butterflies and moths are seen flying from flower to flower, collecting the honey and carrying pollen. I frequently saw them cross the limits of the neighboring beds. Loaded with the pollen of the variety they visit the flowers of the different species and impregnate the stigma with it. And returning to the variety they bring about similar crosses in the flowers of the latter. Hybrid seeds will develop in both cases and become mixed with the crop. We now have to ask the question, what sort of plants will arise from these hybrid seeds. As a general rule we may state, first, that the hybrids of either form of cross are practically the same, secondly that they are not intermediate, but that the character of one parent prevails to the almost absolute exclusion of the other and in the third place that the older character dominates the younger. [209] The hybrid offspring will therefore, in the main, have the character of the species and be indistinguishable from it, or show only such differences as escape ordinary observation. When occurring in the seeds of the variety they betray themselves as soon as the differential characters are displayed. Between the thousands of flowering plants of a white variety the hybrids will instantly catch the eye by their red or blue corollas. Quite the contrary effect results from the admixture of hybrids with the seeds of the species itself. Here no difference will show itself, even in the fullest bloom. The effect of the spontaneous crosses will pass unobserved. The strain, if pure in the first year, will seem to be still in the same condition. Or in other terms, the unavoidable spontaneous crosses will disturb the purity of the variety in the second year, while they do not seem to interfere at all with the uniformity of the species. The direct effect of the visits of the insects is evident in the first case, but passes unobserved in the latter.