P. Lamarck was the first author to work out a connected theory of descent and to suggest that the relationships of organic forms were due to actual affinities.
Moreover, whatever the value of Goethe's labours in that field, they were not published before 1820, long after evolutionism had taken a new departure from the works of Treviranus and Lamarck - the first of its advocates who were equipped for their task with the needful large and accurate knowledge of the phenomena of life as a whole.
Lamarck introduced the conception of the action of an animal on itself as a factor in producing modification.
But a little consideration showed that, though Lamarck had seized what, as far as it goes, is a true cause of modification, it is a cause the actual effects of which are wholly inadequate to account for any considerable modification in animals, and which can have no influence at all in the vegetable world; and probably nothing contributed so much to discredit evolution, in the early part of the 29th century, as the floods of easy ridicule which were poured upon this part of Lamarck's speculation.
Those who were unwilling to accept evolution, without better grounds than such as are offered by Lamarck, and who therefore preferred to suspend their judgment on the question, found in the principle of selective breeding, pursued in all its applications with marvellous knowledge and skill by Darwin, a valid explanation of the occurrence of varieties and races; and they saw clearly that, if the explanation would apply to species, it would not only solve the problem of their evolution, but that it would account for the facts of teleology, as well as for those of morphology; and for the persistence of some forms of life unchanged through long epochs of time, while others undergo comparatively rapid metamorphosis.
Inasmuch as Lamarck attempted to frame a theory of evolution in which the principle of natural selection had no part, the interpretation placed on their work by many bionomical investigators recalls the theories of Lamarck, and the name Neo-Lamarckism has been used of such a school of biologists, particularly active in America.
Exceptions to this attitude are Lamarck, who speaks with regard to animals (but not to plants!) of f la composition croissante de lorganisation (Philoso p/lie zoologique, t.
The position assumed in this article is in agreement with the views of Lamarck and of Nageli.
3 Neither Lamarck nor Robert Chambers (the now acknowledged author of Vestiges of Creation), though thorough evolutionists, rationally indicated any means whereby, to use the old phrase, " the transmutation of species " could be effected.
Lamarck (Animaux sans vertebres, 1801) and G.
ARACHNIDA, the zoological name given in 1815 by Lamarck (Gr.
Lamarck at the same time founded the class Crustacea for the lobsters, crabs and water-fleas, also until then included in the order Aptera of Linnaeus.
Lamarck included the Thysanura and the Myriapoda in his class Arachnida.
It was thus reduced by Lamarck in area, and made to comprise only the six-legged, wing-bearing " Insecta."
For these Lamarck proposed the name Hexapoda; but that name has been little used, and they have retained to this day the title of the much larger Linnaean group, viz.
- General conceptions with regard to the relations of living things (especially animals) to the universe, to man, and to the Creator, their origin and significance: exemplified in the writings of the philosophers of classical antiquity, and of Linnaeus, Goethe, Lamarck, Cuvier, Lyell, H.
P. de Lamarck (1744-1829) represents most completely, both by his development theory (to be further mentioned below) and by his scheme of classifica- tion, the high-water mark of the popular but cation.
The enumeration of orders above given will enable the reader to form some conception of the progress of knowledge relating to the lower forms of life during the fifty odd years which intervened between Linnaeus and Lamarck.
The number of genera recognized by Lamarck is more than ten times as great as that recorded by Linnaeus.
We have mentioned Lamarck before his great contemporary Cuvier because, in spite of his valuable philosophical doctrine of development, he was, as compared with Cuvier and estimated as a systematic zoologist, a mere enlargement and logical outcome of Linnaeus.
Lamarck accepted the development theory fully, and pushed his speculations far beyond the realm of fact.
Cuvier's doctrine of four plans of structure was essentially a morphological one, and so was the single-scale doctrine of Buffon and Lamarck, to which it was opposed.
Lamarck believed in a single progressive series of forms, whilst Cuvier introduced s the conception of branches.
Lamarck had put forward the hypothesis that structural alterations acquired by (that is to say, superimposed upon) a parent in the course of its life are transmitted to the offspring, and that, as these structural alterations are acquired by an animal or plant in consequence of the direct action of the environment, the offspring inheriting them would as a consequence not unfrequently start with a greater fitness for those conditions than its parents started with.
In the course of several generations, Lamarck argued, a structural alteration amounting to such difference as we call " specific " might be thus acquired.
It was not proved by Lamarck that they can be, and, indeed, never has been proved by actual observation.
consequent disuse, and the transmission (as Lamarck would have supposed) of a more and more weakened and structurally impaired eye to the offspring in successive generations, until the eye finally disappeared.
It is a remarkable fact that it was overlooked alike by the supporters and opponents of Lamarck's views until pointed out by the present writer (Nature, 1894, p. 127), that the two statements called by Lamarck his first and second laws are contradictory one of the other.
If a character of much longer standing (certain properties of height, length, breadth, colour, &c.) had not become fixed and congenital after many thousands of successive generations of individuals had developed it in response to environment, but gave place to a new character when new moulding conditions operated on an individual (Lamarck's first law), why should we suppose that the new character is likely to become fixed and transmitted by mere heredity after a much shorter time of existence in response to environmental stimulus ?
Why should we assume that it will be able to escape the moulding by environment (once its evoking cause is removed) to which, according to Lamarck's first law, all parts of organisms are subject ?
Clearly Lamarck gives us no reason for any such assumption, and his followers or latter-day adherents have not attempted to do so.
His most important scientific work is his Zoonomia (1794-1796), which contains a system of pathology, and a treatise on generation, in which he, in the words of his famous grandson, Charles Robert Darwin, "anticipated the views and erroneous grounds of opinions of Lamarck."
P. Lamarck's term Annelides, now used to denote a major phylum or division of coelomate invertebrate animals.
II.-Second Historic Period Invertebrate palaeontology founded by Lamarck, vertebrate palaeontology by Cuvier.
Political troubles and the dominating influence of Werner's speculations checked palaeontology in Germany, while under the leadership of Lamarck and Cuvier France came to the fore.
Lamarck (1744-1829) was the founder of invertebrate palaeontology.
The chief contributions of Cuvier's great philosophical opponent, Etienne Geoffroy St Hilaire (1772-1844), are to be found in his maintenance with Lamarck of the doctrine of the mutability of species.
The pathbreaking works of Lamarck were soon followed by the monumental treatise of Gerard Paul Deshayes (1795-1875) entitled Descriptions des coquilles fossiles des environs de Paris (1824-1837), the first of a series of great contributions by this and other authors.
He thus exerted a potent influence on palaeontology through his persistent advocacy of uniformitarianism, a doctrine with which Lamarck should also be credited.
He thus revived Lamarck's views and helped to found the so-called neoLamarckian school in America.
Starting with the stem forms the descendants of which have passed through either persistent or changed habitats, we reach the underlying idea of the branching law of Lamarck or the law of divergence of Darwin, and find it perhaps most clearly expressed in the words "adaptive radiation" (Osborn), which convey the idea of radii in many directions.
the chemistry of Lavoisier, the zoology of Lamarck, the astronomy of Laplace and the geology of Lyell.
He supposes that this evolution does not remain cosmic, but becomes organic. In accordance with Lamarck's hypothesis, he supposes an evolution of organisms by hereditary adaptation to the environment (which he considers necessary to natural selection), and even the possibility of an evolution of life, which, according to him, is the continuous adjustment of internal to external relations.
Lamarck practically conceded the objective existence of species in arguing that they might be modified by external conditions, and G.
Lamarck in the chair of natural history at the museum.
The difference between Lamarck's theory and natural selection is very clearly pointed out.
With such clear statements as these in the paper of the 1st of July 1858, it is remarkable that even well-known naturalists should have failed to comprehend the difference between Lamarck's and the Darwin-Wallace theory.
Darwin died some years before the controversy upon the possibility of the hereditary transmission of acquired characters arose over the writings of Weismann, but Wallace has freely accepted the general results of the German zoologist's teaching, and in Darwinism has presented a complete theory of the causes of evolution unmixed with any trace of Lamarck's use or disuse of inheritance, or Buffon's hereditary effect of the direct influence of surroundings.
In the 19th century, however, Lamarck's theory of the development of new species by habit and circumstance led through Wallace and Darwin to the doctrines of the hereditary transmission of acquired characters, the survival of the fittest, and natural selection.
Typical genera - Stylina, Lamarck (Jurassic).
Typical genera - Pocillopora, Lamarck.
We have, in fact, returned very nearly to Cuvier's conception of a great division or branch, which he called Articulata, including the Arthropoda and the Chaetopoda (Annelides of Lamarck, a name adopted by Cuvier), and differing from it only by the inclusion of the Rotif era.
Lamarck's penetrating genius is chiefly responsible for the shrinkage of the word Insecta, since it was he who, forty years after Linnaeus's death, set up and named the two great classes Crustacea and Arachnida (included by Linnaeus under Insecta as the order " Aptera "), assigning to them equal rank with the remaining Insecta of Linnaeus, for which he proposed the very appropriate class-name " Hexapoda."
Lamarck, however, appears not to have insisted on this name Hexapoda, and so the class of Pterygote Hexapods came to retain the group-name Insecta, which is, historically or etymologically, no more appropriate to them than it is to the classes Crustacea and Arachnida.
Lamarck in 1809 altered this into the hybrid form Cirrhipoda, meaning curl-footed, which was subsequently improved into Cirripedia or Cirrhipedia.
And it is hard to say whether Lamarck or Treviranus has the priority in propounding the main thesis of the doctrine of evolution; for though the first volume of Treviranus's Biologie appeared only in 1802, he says, in the preface to his later work, the Erscheinungen and Gesetze des organischen Lebens, dated 1831, that he wrote the first volume of the Biologie " nearly five-and-thirty years ago," or about 1796.
Lamarck, while affirming the verbal proposition that animals form a single series, was forced by his vast acquaintance with the details of zoology to limit the assertion to such a series as may be formed out of the abstractions constituted by the common characters of each group.'
As Lamarck has well said:-2 " 11 n'y a que ceux qui se sont longtemps et fortement occupes de la determination des especes, et qui ont consulte de riches collections, qui peuvent savoir jusqu'a quel point les especes, parmi les corps vivants, se fondent les unes dans les autres, et qui ont pu se convaincre que, dans les parties oft nous voyons des especes isolees, cela n'est ainsi que parcequ'il nous en manque d'autres qui en sont plus voisines et que nous n'avons pas encore recueillies.
Lamarck, Treviranus, Erasmus Dar win, Goethe, and Saint-Hilaire preached to deaf ears, for they advanced the theory that living beings had developed by a slow process of transmutation in successive generations from simpler ancestors, and in the beginning from simplest formless matter, without being able to demonstrate any existing mechanical causes by which such development must necessarily be brought about.
The familiar illustration of Lamarck's hypothesis is that of the giraffe, whose long neck might, he suggested, have been acquired by the efforts of a primitively short-necked race of herbivores who stretched their necks to reach the foliage of trees in a land where grass was deficient, the effort producing a distinct elongation in the neck of each generation, which was then transmitted to the next.
Lamarck's first law asserts that a past history of indefinite duration is powerless to create Educa- a bias by which the present can be controlled.
Principles of descent and other applications of uniformitarianism which had been struggling for expression in the writings of Lamarck, St Hilaire and de Blainville here found their true interpretation, because the geological succession, the rise, the migrations, the extinctions, were all connected with the grand central idea of evolution from primordial forms.
He says Lamarck's original animal is something metaphysical, not physical, namely, the will to live.
Now, in 1794, there is evidence that Lamarck held doctrines which present a striking contrast to those which are to be found in the Philosophic zoologique, as the following passages show: " 685.
The Recherches sur l'organisation des corps vivants, which sketches out Lamarck's doctrines, was published in 1802; but the full development of his views in the Philosophic zoologique did not take place until 1809.
In the preface, Lamarck says that the work was written in 1776, and presented to the Academy in 1780; but it was not published before 2794, and at that time it presumably expressed Lamarck's mature views.
For many years it was the fashion to speak of Lamarck with ridicule, while Treviranus was altogether ignored.
If we seek for the reason of the difference between the scientific position of the doctrine of evolution in the days of Lamarck and that which it occupies now, we shall find it in the great accumulation of facts, the several classes of which have been enumerated above, under the second to the eighth heads.
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