Vietnam or Thailand ? Vote for the TOP Country of the Week !
Updated: May 16, 2025
And to this it should be added that really progressive mutations have hardly been observed in horticulture. Hence the theoretical value of the facts is far less than might have been expected. The steady cooperation of progression and retrogression is one of the important principles of organic evolution. I have dwelt upon this point more than once in previous lectures.
Doubtless, mutations have occurred in antlers as in other characters; in fact all hereditary characters are subject to mutation.
Two cases of sudden mutations have come to my knowledge, producing this same anomaly in allied species. One has been already alluded to; it pertains to the common evening-primrose or Oenothera biennis, and one is a species belonging to another genus of the same family, the great hairy willow-herb or Epilobium hirsutum.
The other method is the gradual accumulation of those always present and ever fluctuating variations which are indicated by the common assertion that no two individuals of a given race are exactly alike. The first changes are what we now call "mutations," the second are designated as "individual variations," or as this term is often used in another sense, as "fluctuations."
The ancient monarchy of France, and all the old ordering of which the monarchy had been the keystone, was overthrown, and it was not until after many a violent shock of arms, after terrible slaughter of men, after strange diplomatic combinations, after many social convulsions, after many portentous mutations of empire, that Europe once more settled down for a season into established order and system.
But what were they to us, amid those mutations of fortune, which, at one moment, made us princes, and placed palaces at our control, and, at another, debased us below the veriest beggar, that craves the stinted alms of charity from door to door. "And there was one man who, from the first to the last, stayed by us like a very fiend; more than man, I thought he was not human.
She is a noble-hearted girl for uttering those words. A dreadful incident in our family has occurred, which might well induce you to pause before uniting your fate with that of any member of it." "Impossible. Nothing can possibly subdue the feelings of affection I entertain for Flora. She is worthy of any one, and, as such, amid all changes all mutations of fortune, she shall be mine."
It is readily granted that such special preparation may occur, because the great numbers in which our dwarf variety of the Oenothera are yearly produced are suggestive of such a condition. On the other hand, the laevifolia and brevistylis mutations have not been repeated, at least not in a visible way.
Certainly, whether or no we learn how to change the nature of germplasm within a short time, we have in the endocrines the means at hand for affecting the whole individual that is born and sees the light of day. The true physical and intellectual evolution of man depends upon the production of mutations of a desirable kind that can survive.
In these three species therefore, apart from mutations, the northern forms all show a greater development of spines on the scales. Whether this is an effect of colder temperature it is difficult to say.
Word Of The Day
Others Looking