Vietnam or Thailand ? Vote for the TOP Country of the Week !
Updated: June 23, 2025
It is simply the extension of the pedigree of the evening-primroses backward through ages, with the same construction and the same leading features. There can be no doubt that we are quite justified in assuming that evolution has followed the same general laws through the whole duration of life on earth.
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.
Indeed, if it should once become possible to bring plants to mutate at our will and perhaps even in arbitrarily chosen directions, there is no limit to the power we may finally hope to gain over nature. What is to guide us in this new line of work? Is it the minute inspection of the features of the process in the case of the evening-primroses?
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.
No large group and probably even no genus or large species has been evolved without the joint agency of these two great principles. In the mutation-period of the evening-primroses the observed facts give direct support to this conclusion, since some of the new species proved, on closer inspection, to be retrograde varieties, while others manifestly owe their origin to progressive steps.
First are to be cited those species which have been introduced from America into Europe since the time of Columbus, or from Europe into this country. Some of them have become very common. In my own country the evening-primroses and Canada fleabane or are examples, and many others could be given. They should be expected to vary under these circumstances in a larger degree. Have they done so?
Of course a direct proof of this view cannot, as yet, be given, but this conclusion is forced upon us by a consideration of known facts bearing on the principle of constancy and evolution. If we are right in this general conception, we may ask further, what is to be the exact place of our group of new evening-primroses in this theory?
The assumption seems justified that analogous cases will be met with, perhaps even in larger numbers, when similar methods of observation are used in the investigation of plants of other regions. The mutable condition may not be predicated of the evening-primroses alone.
But why this should affect the foliage in one manner, the flowers in another and the fruits in a third direction, remains obscure. To gain ever so little an insight into the nature of these changes, we may best compare the differences of our evening-primroses with those between the two hundred elementary species of Draba and other similar instances.
Word Of The Day
Others Looking