Specie

“ The meaning attached to the term species, in natural history, is very simple and obvious. It includes only one circumstance—namely, an original distinctness and constant transmission of any character. A race of animals, or plants, marked by any peculiarities of structure which have always been constant and undeviating, constitutes a species. ”

“ Granting individual variability, then, how do species arise in nature? And how are all the exquisite adaptations of part to whole, and of whole to environment, gradually initiated, improved, and perfected? ”

“ From the above considerations, it appears that species have a real existence in nature; and that each was endowed, at the time of its creation, with the attributes and organization by which it is now distinguished. ”

“ When we look to the individuals of the same variety or sub-variety of our older cultivated plants and animals, one of the first points which strikes us, is, that they generally differ much more from each other, than do the individuals of any one species or variety in a state of nature. ”

“ On the ordinary view of each species having been independently created, why should specific characters, or those by which the species of the same genus differ from each other, be more variable than the generic characters in which they all agree? ”

“ Many people think of zoology as it was in the time of Linnæus, or, at best, as it was in the early part of the nineteenth century, when the spiritless activity of species-making was its prominent feature. ”

“ Reasoning from analogy and from the different varieties of the same species, and the different species under one genus, among all other animals, he pointed out their different modes of living, and the different designs of the Creator, that appeared to be evinced with respect to them. ”

“ How much of the acclimatisation of species to any peculiar climate is due to mere habit, and how much to the natural selection of varieties having different innate constitutions, and how much to both means combined, is an obscure question. ”

“ But, besides the fortunes of individual plants and animals, there is another class of questions, of great interest, but of great difficulty;—the fortunes of each species. In what manner do species which were not, begin to be? as geology teaches us that they many times have done; and, as even our own reasonings convince us they must have done, at least in the case of the species among which we live. ”

“ In his most recent work 'On the Origin of Species,' although opinions may be divided or undecided with respect to its merits in some respects, all will allow that it contains a mass of observations bearing upon the habits, structure, affinities, and distribution of animals, perhaps unrivalled for interest, minuteness, and patience of observation. ”

“ The forms which possess in some considerable degree the character of species, but which are so closely similar to other forms, or are so closely linked to them by intermediate gradations, that naturalists do not like to rank them as distinct species, are in several respects the most important for us. We have every reason to believe that many of these doubtful and closely allied forms have permanently retained their characters for a long time; for as long, as far as we know, as have good and true species. ”

“ The facts of variability, of the struggle for existence, of adaptation to conditions, were notorious enough; but none of us had suspected that the road to the heart of the species problem lay through them, until Darwin and Wallace dispelled the darkness, and the beacon-fire of the 'Origin' guided the benighted. ”

“ Hence it is the most flourishing, or, as they may be called, the dominant species,— those which range widely, are the most diffused in their own country, and are the most numerous in individuals,— which oftenest produce well-marked varieties, or, as I consider them, incipient species. ”

“ If we now look upon the definition of a species, as given by a gentleman foremost in the ranks as a describer of species, we find it formulated as follows: A species represents "a primary established law, stamped with a persistent form (a type) pertaining solely to itself, with the power of successively reproducing the same form, and none other;" ”

“ The continual development of species by the formation of new varieties here produces a mass of intermediate forms which connect the so-called “good” species, which efface their boundaries, and render their sharp specific distinction completely illusory. ”

“ I believe that a careful consideration of the structure of a species, and of the peculiar physical and organic conditions by which it is surrounded, or has been surrounded in past ages, will often, as in this case, throw much light on the origin of its habits and instincts. ”

“ A species, in the usual acceptation of the term, is an animal which, in a state of nature, is distinguished by certain peculiarities of form, size, colour, or other circumstances, from another animal. ”

“ Hitherto naturalists had considered kinds of animals and plants, or species as they are more properly called, to have been specially created as they are seen by us, and that they were unalterable and invariable. ”

“ It has, therefore, been proposed entirely to reject descent as an element in the definition of species, and to consider as such any set of individuals which present, either in their external form, or in their internal structure, or in their biological phenomena, any common character, or combination of characters, distinguishing them from all others. ”

“ But animals or plants which thus differ in a state of nature are always classed as distinct species, and thus we see how, by the continuous survival of the fittest or the preservation of favoured races in the struggle for life, new species may be originated. ”

“ From these remarks it will be seen that I look at the term species, as one arbitrarily given for the sake of convenience to a set of individuals closely resembling each other, and that it does not essentially differ from the term variety, which is given to less distinct and more fluctuating forms. ”

“ Having now obtained some notion of how animals are dispersed over the earth's surface, whether as single species or as collected in those groups termed genera, families, and orders, it will be well, before proceeding further, to understand something of the classification of the facts we have been considering, and some of the simpler conclusions these facts lead to. ”

“ Who can explain why one species ranges widely and is very numerous, and why another allied species has a narrow range and is rare? Yet these relations are of the highest importance, for they determine the present welfare and, as I believe, the future success and modification of every inhabitant of this world. ”

“ The sounder view is, as scientific writers have frequently insisted, that living species have varied along divergent lines from intermediate forms, and, as it is the object of this paper to point out, not necessarily in an upward direction. ”

“ The proof that all the members of any given group of animals, or plants, had thus descended, would be ordinarily considered sufficient to entitle them to the rank of physiological species, for most physiologists consider species to be definable as “the offspring of a single primitive stock.” ”

“ Species is in the animal kingdom that which copulates without necessity and compulsion. The same definition is applicable to plants. The species range, without doubt, according to the diversities in the individual organs themselves, which admit of a great multitude of combinations, the number of which is not as yet to be determined. ”

“ Creatures are brought from the extremities of the earth—the polar, temperate, and tropical denizens, all mixed up and crossed with each other—food, climate, and treatment, all changed—and, through all, the type of every species continues as before—no transmutation of one kind into another under all the violent tutoring agencies to which they have been subjected. ”

“ However bare and simple this definition of species may appear to be, we confidently appeal to all practical naturalists, whether zoologists, botanists, or palaeontologists, to say if, in the vast majority of cases, they know, or mean to affirm, anything more of the group of animals or plants they so denominate than what has just been stated. ”

“ How can we deal with such a large subject in a brief way? It seems best to confine our attention in this chapter to an attempt to answer the question, What is a species? and are "species" natural groups clearly delimited by nature? ”

“ As to the first point, of varieties existing among natural species, I might appeal to the universal experience of every naturalist, and of any person who has ever turned any attention at all to the characteristics of plants and animals in a state of nature ”

“ One is that the plants and animals now existing mostly differ from the plants and animals which have existed. Though there are species common to our present Fauna and to past Faunas, yet the facies of our present Fauna differs, more or less, from the facies of each past Fauna. ”

“ And we can clearly understand these analogies, if species have once existed as varieties, and have thus originated: whereas, these analogies are utterly inexplicable if each species has been independently created. ”

“ The original types of all the older species I shall certainly make out; but the limitation of the species presents great, if not insuperable difficulties.
I have read nearly all of Darwin’s “Power of Movement in Plants.” ”

“ The exact proportions of the various species of plants, the numbers of each kind of insect or of bird, the peculiarities of more or less exposure to sunshine or to wind at certain critical epochs, and other slight differences which to us are absolutely immaterial and unrecognisable, may be of the highest significance to these humble creatures, and be quite sufficient to require some slight adjustments of size, form, or colour, which natural selection will bring about. ”

“ The most general answer to this question used to be the following: “To one species belong all those individuals which agree in all essential characteristics. Essential characteristics of species are those which remain permanent or constant, and never become modified or vary.” ”

“ He told me how varieties in animals gradually develop into species; how certain causes, which in brief periods produce varieties, in long periods give rise to types; how the colors of animals are useful for concealment from their prey ”

“ Nature must be studied in detail, and it is the wonderful variety of the species of a group, their complicated relations and their endless modification of form, size and colours, which constitute the pre-eminent charm of the entomologist's study. ”

“ Referring to such cases, he remarks, "It is difficult to comprehend the meaning of such facts as these, if we suppose that each species of animal and plant, or each great type of organisation, was formed and placed upon the surface of the globe at long intervals by a distinct act of creative power ”

“ Once we have gained the fundamental conceptions as to what is meant by a "species," we are able intelligently to consider innumerable facts of the most diverse kind as to their peculiar structure and colours, their number, localities, their interaction and dependence on other living things, their modifications for special modes of life, their isolation or their ubiquity. ”

“ The whole science of the evolution of man and the other animals is intimately connected with the question of the nature of species, or with the problem of the origin of the various animals which we group together under the name of species. ”