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In connection with these characters, the flower-buds are seen to be much stouter than those of lamarckiana. The fruits attain only half the normal size, but are broader and contain fewer, but larger seeds. The rubrinervis is in many respects a counterpart to the gigasv, but its stature is more slender. The spikes and flowers are those of the lamarckianav, but the bracts are narrower.
Unfortunately they are very sensitive, especially to wet weather. Oenothera gigas and O. rubrinervis, or the giant, and the red-veined evening-primroses, are the names given to two robust and stout species, which seem to be equal in vigor to the parent-plant, while diverging from it in striking characters.
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.
The gigas, as a rule, produces far more, and the rubrinervis far less biennial plants than the lamarckiana. Annual culture for the one is as unreliable as biennial culture for the other. Rubrinervis may be annual in apparently all specimens, in sunny seasons, but gigas will ordinarily remain in the state of rosettes during the entire first summer.
Moreover I observed that the attributes of lata and nanella, which I now studied in the offspring of my first mutants, were clearly discernible in extreme youth, while those of rubrinervis remained concealed some weeks longer. Hence I concluded that the young plants should be examined from time to time until they proved clearly to be only normal lamarckiana.
From this they have inherited the mutability or the capacity of producing at their turn new mutants. But they seem to have done so incompletely, changing in the direction of more absolute constancy. This was especially observed in the case of rubrinervis, which is not of such rare occurrence as O. gigas, and which it has been possible to study in large numbers of individuals.
It would be worth while to see whether the climate of California, where neither O. lamarckiana nor O. biennis are found wild, would not exactly suit the requirements of the new species rubrinervis and gigas. A fixed hybrid between O. cruciata and O. biennis constituting a species has been in cultivation for many years.
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.
These three new forms are therefore considered to constitute only retrograde steps, and no advance. This conclusion has been fully justified by some crossing experiments with brevistylis, which wholly complies with Mendel's law, and in one instance with nanella, which behaves in the same manner, if crossed with rubrinervis.
As was to be expected, lata and nanella were repeated in this third generation . I was sure to get nearly all of them, without any important exceptions, as I now knew how to detect them at almost any age. In fact, I found many of them; as many as 60 nanella and 73 lata, or nearly 5% of each. Rubrinervis also recurred, and was seen in 8 specimens.
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