Taxon

“ The contrasting patterns in the description of new species and new higher taxa suggest that taxonomic effort is probably not driving observed flattening of accumulation curves in higher taxonomic levels as there is at least sufficient effort to maintain a constant description of new species. ”

“ Coues on the taxonomy of birds: "The student cannot be too well assured that no such things as species, in the old sense of the word, exist in nature any more than have genera or families an actual existence. ”

“ Also, when studying the ecological relations of some taxonomic unit, as in aggregate ecology, the number of associates is so large that one must do rather extensive collecting. But even the exhaustive study of the behavior of any single species will necessitate considerable collecting. ”

“ For taxonomy the tree notion of descent was sufficient as a means of indicating the history and affinities of species and higher groups, but evolution is a process which must be studied inside the species, and here the diagram of relationship is not dentritic, but reticular. ”

“ In the one case we study fossils in taxonomic groups—i.e., as species, genera, families, orders, etc.—and trace the gradual evolution of each of these from generalized forms to their specialized outcomes, completing as far as possible the genetic chain through all time. In the other we study fossils in faunal groups, as successive geological faunas, and the geographic diversity in each geological period—i.e., the evolution of geologic faunas and the causes of geographic diversity in each. ”

“ Order, Class, Genus, and Species.
Order, is a general term, applicable to a whole race of animals, whereby they are distinguished from each other, as beasts, birds, fishes, &c. [13]
Class, a term by which insects, as well as other animals, are divided into their respective genera or tribes, as the farinaceous, crustaceous, transparent, &c. [14]
Genus, a term dividing each class, as butterfly, moth, hawk-moth, constitute the farinaceous (Lepidoptera) ; dung-beetle, lady-bird, goat-chaffer, and many others, make up the crustaceous (Coleoptera) ”

“ Among animals which unite for each birth, and which are highly locomotive, doubtful forms, ranked by one zoologist as a species and by another as a variety, can rarely be found within the same country, but are common in separated areas. How many of the birds and insects in North America and Europe, which differ very slightly from each other, have been ranked by one eminent naturalist as undoubted species, and by another as varieties, or, as they are often called, geographical races! ”

“ First in order of importance comes the fact that not only are there uniformly transmitted from an organism to its offspring, those traits of structure which distinguish the class, order, genus, and species; but also those which distinguish the variety. We have numerous cases, among both plants and animals, where, by natural or artificial conditions, there have been produced divergent modifications of the same species; and abundant proof exists that the members of any one sub-species habitually transmit their distinctive peculiarities to their descendants. ”

“ When two groups of species differ from each other constantly in one or more of these latter particulars they are said to belong to different genera. We have already seen that species vary in these more important as well as in the more superficial characters. If, then, in any part of the area occupied by a species some change of habits becomes useful to it, all such structural variations as facilitate the change will be accumulated by natural selection, and when they have become fixed in the proportions most beneficial to the animal, we shall have the first species of a new genus. ”

“ A single specimen, perhaps, of a dried plant, or a stuffed bird or quadruped; a shell, without the soft parts of the animal; an insect in one stage of its numerous transformations;—these are the scanty and imperfect data which the naturalist possesses. Such information may enable us to separate species which stand at a considerable distance from each other; but we have no right to expect any thing but difficulty and ambiguity, if we attempt, from such imperfect opportunities, to obtain distinctive marks for defining the characters of species which are closely related. ”

“ As to the alleged absence of intermediate varieties connecting one species with another, every zoologist and botanist who has engaged in the task of classification has been occasionally thrown into this dilemma—if I make more than one species in this group, I must, to be consistent, make a great many. ”

“ All the phenomena presented by the species of a genus are reproduced by the genera of a family, and often in a more marked degree. Owing, however, to the extreme restriction of genera by modern naturalists, there are not many among the higher animals that have a world-wide distribution. ”

“ Close investigation, in most cases, will bring naturalists to an agreement how to rank doubtful forms. Yet it must be confessed, that it is in the best-known countries that we find the greatest number of forms of doubtful value. I have been struck with the fact, that if any animal or plant in a state of nature be highly useful to man, or from any cause closely attract his attention, varieties of it will almost universally be found recorded. These varieties, moreover, will be often ranked by some authors as species. ”

“ It will generally be found that the parts in our domesticated productions which have varied, or which still continue to vary,—that is, which fail to retain their primordial state,—are the same with the parts which differ in the natural species of the same genus. ”

“ We may look in vain through the 288 known species [4] for a beak so small and conical as that of the short-faced tumbler; for one so broad and short as that of the barb; for one so long, straight, and narrow, with its enormous wattles, as that of the English carrier; for an expanded upraised tail like that of the fantail; or for an œsophagus like that of the pouter. I do not for a moment pretend that the domestic races differ from each other in their whole organisation as much as the more distinct natural genera. ”

“ The disposition of wild animals undoubtedly differs. The variation, such as it is, chiefly affects the same parts in wild organisms as in domestic breeds; for instance, the size, colour, and the external and less important parts. In many species the variability of certain organs or qualities is even stated as one of the specific characters: thus, in plants, colour, size, hairiness, the number of the stamens and pistils, and even their presence, the form of the leaves; the size and form of the mandibles of the males of some insects ”

“ By specimen after specimen has every stage of growth and every degree of development been exemplified; and the Palæontologist has come as thoroughly to know the creatures, in consequence, under their various changes from youth to age, as if they had been his contemporaries, and had grown up under his eye. And had our existing species, vegetable and animal, been derived from other species of the earlier periods, it would have been equally possible to demonstrate, by a series of specimens, their relationship. Let us again instance the British shells. ”

“ In the preceding list, when all the specimens I have seen from a particular habitat have a similar and peculiar character, I have considered them as species; on the contrary when the specimens from the same locality offer variations among themselves, as in those of the genus Hepoona, where the extent of the whiteness on the tail, and the variation in the colour of the body appear to differ in the specimens from the same place, I have regarded them as belonging to the same species, believing it to be a variable species which has an extensive range. ”

“ After this glance at the variations peculiar to each species, a more important consideration presents itself, that of the change of the species themselves; that ancient and immemorial degeneration made in each family, or in every genus, under which we may comprehend the proximating species. Among all terrestrial animals there are only a few detached species, which, like the human, at once compose both species and genus. ”

“ By the theory of natural selection all living species have been connected with the parent-species of each genus, by differences not greater than we see between the natural and domestic varieties of the same species at the present day ”

“ How do varieties, or as I have called them incipient species, become converted into true and well-defined species? How has each new species been adapted to the surrounding physical conditions, and to the other forms of life on which it in any way depends? We see on every side of us innumerable adaptations and contrivances, which have justly excited in the mind of every observer the highest admiration. ”

“ Independently of all general methods of classification, whether natural or artificial, plants, as well as animals, are distinguished into Genera [1] , Species, and Varieties.
By Species are understood so many individuals, or, among the generality of animals, so many pairs, as are presumed to have been formed at the creation, and have been perpetuated ever since; for though some animals appear to have been exterminated, we have no reason to suspect any new species has been produced ”

“ I have discussed this subject of analogous variation at considerable length, because, in a future work on natural species, it will be shown that the varieties of one species frequently mock distinct species—a fact in perfect harmony with the foregoing cases, and explicable only on the theory of descent. ”

“ It is a truly wonderful fact—the wonder of which we are apt to overlook from familiarity—that all animals and all plants throughout all time and space should be related to each other in group subordinate to group, in the manner which we everywhere behold—namely, varieties of the same species most closely related together, species of the same genus less closely and unequally related together, forming sections and sub-genera, species of distinct genera much less closely related, and genera related in different degrees, forming sub-families, families, orders, sub-classes, and classes. ”

“ When we compare 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 more from each other than do the individuals of any one species or variety in a state of nature. And if we reflect on the vast diversity of the plants and animals which have been cultivated, and which have varied during all ages under the most different climates and treatment, we are driven to conclude that this great variability is due to our domestic productions having been raised under conditions of life not so uniform as, and somewhat different from, those to which the parent species had been exposed under nature. ”

“ He plucked the plants one after another, danced, hugged me in his arms, and exultingly told me that he had got not merely a new species, but a new genus. When we returned home, the naturalist opened the bundle which he had brought on his back, and took out a journal rendered water-proof by means of a leather case, together with a small parcel of linen, examined the new plant, and wrote its description. ”

“ When two or more species of any genus now inhabit the same waters, they are usually species whose differentiation is of long standing,—species, therefore, which can be readily distinguished from one another. ”

“ Observation further acquaints us with the fact, that, sometimes, an individual member of a species may exhibit a more or less marked variation, which is propagated through all the offspring of that individual, and may even become intensified in them. And, in this manner, a variety, or race, is generated within the species; which variety, or race, if nothing were known respecting its origin, might have every claim to be regarded as a separate morphological species. ”

“ 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. ”

“ It appeared necessary in composing the History of Wild Animals, to consider them one by one, and independently of genus; but on the contrary, in domestic animals, it appears requisite even to extend the genera; because, in Nature, there only exists individuals, and [70] succession of individuals, that is, species. ”

“ This gradual increase in number of the species of a group is strictly conformable with the theory; for the species of the same genus, and the genera of the same family, can increase only slowly and progressively ”

“ We use the term species, to designate a number of individual plants, which, in all essential and unvarying characters, resemble each other more closely than they do any other plant; the term genus or kind, to designate an assemblage of nearly allied species, agreeing with one another in general structure and appearance more closely than they do with any other species. ”

“ Yet if we compare a cabbage rose with a wild rose, a golden pippin apple with a crab, a toy terrier with any species of wild dog, not to mention any number of other instances, there can be no question that, if such differences had appeared in nature, the organisms presenting them would have been entitled to rank as distinct species—or even, in many cases, as distinct genera. ”

“ It may be safely assumed that our readers have a general conception of the nature of the objects to which the word "species" is applied; but it has, perhaps, occurred to a few, even to those who are naturalists 'ex professo', to reflect, that, as commonly employed, the term has a double sense and denotes two very different orders of relations. When we call a group of animals, or of plants, a species, we may imply thereby, either that all these animals or plants have some common peculiarity of form or structure ”