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Briefly considering the different forms, we may state that the full experimental proof has been given for the origin of gigas and rubrinervis, for albida and oblonga, and even for nanella, which is to be considered as of a varietal nature; with lata the decisive experiment is excluded by its unisexuality. laevifolia and brevistylis were found originally in the field, and never appeared in my cultures.
Leaving the robust novelties, we may now take up a couple of forms, which are equally constants and differentiated from the parent species in exactly the same manner, though by other characters, but which are so obviously weak as to have no manifest chance of self maintenance in the wild state. These are the whitish and the oblong-leaved evening-primroses or the Oenothera albida and oblonga.
The Tolis are indeed a relic of pure Hinduism of aboriginal spirit-belief, and have in the course of centuries been gradually associated with the great Mahomedan Festival of Tears. "Albida, re albida, Ya Huseini albida." "Farewell, farewell, ah, my Husein, farewell!" It was quite evident that something was seriously wrong with Abdulla the Dhobi.
Today I have only to show that the mutations of the evening-primroses, though sudden, comply with the demands made by Darwin as to the form of variability which is to be accepted as the cause of evolution and as the origin of species. Some of my new types are stouter and others weaker than their parents, as shown by gigas and albida. Some have broader leaves and some narrower, lata and oblonga.
Oenothera albida is a very weak species, with whitish, narrow leaves, which are evidently incapable of producing sufficient quantities of organic food. The young seedling-plants are soon seen to lag behind, and if no care is taken of them they are overgrown by their neighbors.
But an enthusiastic novice counted the flowers blooming one day on that huge mass of Loelia albida yonder, and they numbered two hundred and eleven unless, as some say, this was the quantity of "spikes," in which case one must have to multiply by two or three. Such incidents maybe taken for granted at the farm.
Albida, nanella and rubrinervis appeared in large numbers, and even scintillans, of which I had but a single plant in the previous generation, was repeated sixfold. New forms did not arise, and the capacity of my strain seemed exhausted.
The three first generations were biennial, but the five last annual. Gener: O.gig. albida obl. rubrin. Lam. nanella lata. scint. It is most striking that the various mutations of the evening-primrose display a great degree of regularity. There is no chaos of forms, no indefinite varying in all degrees and in all directions.
If there had been any visible preparation towards the coming mutation, it could not have escaped observation. Moreover, if visible preparation were the rule, it could hardly go on at the same time and in the same individuals in five or six diverging directions, producing from one parent, gigas and nanella, lata and rubrinervis, oblonga and albida and even scintillans.
On the other hand, gigas and rubrinervis, oblonga and albida obviously bear the characters of progressive elementary species. They are not differentiated from lamarckiana by one or two main features. They diverge from it in nearly all organs, and in all in a definite though small degree.
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