Page:The New International Encyclopædia 1st ed. v. 11.djvu/787

* LAMAKCK. 713 LAMARCKISM. tarian. Lamarck lived a life of hard work, with much high thinking, and sadness, scarcity of money, neglect, and bereavement never dampened his courage. The continued and too prolonged study of minute objects through the magnifying lens brought on blindness. l''or the last ten years of his long life he was compelled to rely on an amanuensis. The last two volumes of his Animaux suns verti-bres were dictated to his daughter, Comelie. Lamarck was a man of exceedingly fine char- acter, generous, free from jealousy and self- assertion. He was patriotic, im[)erturbable under the attaints of fortune, and patient under affliction. His mind was essentially philosophic, broad, and synthetic; he was a bold thinker, and ii; every respect an epoch-making man. He died December 18, 1829, at the age of eighty-five years. BlBLiocEAPiiY. The Eloge of Lamarck, by Cu- vier; Martins, "Un naturaliste philosophe ; La- marck, sa vfie et ses a'uvres," in li'ciuie dcs Deux Moiules (Paris, 1873) ; Dc Mortillet and others, Liiinarck: Par un groupe de tfansformistr.% ses discipU-s (reprinted from L'hominc, vol. iv., Paris, 1887); Packard, Ldmnrclc, the Founder of Evolution, His Life and Work, ii:ith Transla- tiuns of His Writings on Organic Evolution ( ew York, 1901). For Lamarck's views on evolution, see Lamarckism. LAMARCKISM. The doctrine of .T. B. P. A. Lamarck (q.v.), which considers the fundamental or primary factors of evolution in the trans- formation of species. Lamarck claimed that all living beings arose from germs, through spon- taneous genei'ation, and that the most primitive was monad-like. In his opinion the first germs of plants and animals were formed in favorable places and under favorable circumstances. The functions of life beginning and an organic move- ment established, these germs "necessarily grad- ually developed the organs, so that after a time and under suitable circumstances they have been ditTerentiated" into parts or organs, develop- ment proceeding from the simple to the com- )ile. He postulated great length of time, so great "that it is absolutely beyond the power of man to appreciate it in an adequate way." He adds that "with the aid of sufficient time, of cir- c:mstances which have been necessarily favor- able, of changes of condition that every part of the earth's surface has successively undergone — ill a word, by the power which new situations and new habits have of modifying the organs of living beings — all those which now exist have been gradually formed such as we now see them." Vestigi.Tl organs are explained as remains ot parts which had been actively used by the an- cestors of existing fcu'ms, but which have be- come atmiihied by disuse. The fact of variation is fnllv appreciated, as also adaptntifiii to needs. In his opinion specific characters vary most. He points out that the nerijihcral parts, as the legs, inonth-parts, antenn;r, etc.. are first affected bv the causes which produce variations, while it requires a longer time for variation in the in- ternal organs to take place. He also insisted that when the conditions of existence remain constant, species do not vary. Lamarck's factors of organic evolution were seven, as follows: (I) KfTects of favorable cir- cumstances due to changes of environment, of climate, soil, food, temperature, etc. Such changes are direct in the case of plants and the lowest animals, but indirect in the ease of the higher animals and man. (2) Needs, new physical wants or necessities induced by change of the conditions of life, result ill the production of new propensities, new habits and functions. Lamarck showed that change of habits may lead to the origination or modifica- tion of organs; that changes of functions also modify or create new organs. He said: "It is easy to demonstrate by observation that uses or habits have given rise to forms," which is an- other expression for Geoifroy Saint-Hilaire's "C'est la fonction qui cr^e I'organ," and an an- ticipation of Dohrii s principle of change of func- tion as a means of modification of organs. (See FuNCTlOX-CllANGE. ) Lamarck's use of the word need or necessity (besoiii) has lieen greatly mis- understood and caricatured. He shows, however, that by change of environment animals are sub- jected to new surroundings, involving new ways and means of living. Thus certain land birds driven by necessity (hesoin) to obtain their food in the water, -gradually assumed characters, or structures, adapting them for swimming, wad- ing, or for searching for food in the shallow water, as in the case of the long-necked kinds. (3) l^se and disuse. The continual use or ex- ercise of organs develops them, as in the wings of birds, etc. The second of these principles he illustrates by the cases of the mole, the whale- bone whales, whose rudimentary teeth exist in the embryo, the ant-eater, the lilind Proteus of caves, the eyeless bivalves, and the snakes, whose ancestors lost their limbs in the process of be- coming adapted for gliding through brush or grass or similar obstacles, (4) The doctrine of the struggle for existence and of competition was stated by Lamarck. He frequently refers to the precautions that nature has takeii to place limits to the too great increase in individuals, and the consequent overcrowd- ing of the earth. The stronger and better armed, he .says, devour the weak, the large animals de- vour the smaller. The multiplication of the smaller species is so rapid that these smaller species render the earth inliabitable for others, but their length of life is very short, and nature always preserves them in just jiroportions not only for their own preservation, but also for that of other species. The larger species, however, nuilti|)ly slowly, and thus is preserved the kind of equilibrium which should exist, (5) Lamarck's characteristic doctrine is the inheritance of characters acquired during the life- time of the individual. (See I'.seIxiiiciutaxck. 1 This by some writers is regarded as if the only feature of Lamarckism. but in reality he discusses the subject very brielly. yet it a])pears to be a necessary result of the action of use and disuse, and of change of anv of the conditions of life. ((')) The efi'ccts of crossing were considered by Lamarck, and — what has been overlooked by commentators and critics — he clearly insists on the leveling or swamping effects of free inter- crossing. He anticipated much modern discussion in his statement: "If. when any peculiarities of form or any defects whatsoever are acquired, the individuals in this case always pairing, they will reproduce the same peculiarities, and if for successive generations confined to such unions, a special and distinct race will then be formed.