trees.

tive ana tomy.

old quarrel between evolution and epigenesis. The most striking | description of the condition of an organ, on the evidence of a general change has been against seeing in the facts of ontogeny single specimen. Naturalists who deal specially with museum any direct evidence as to phylogeny. The general proposition collections have been compelled, it is true, for other as to a parallelism between individual and ancestral development reasons to attach an increasing importance to what is Compara is no doubt indisputable, but extended knowledge of the very called the type specimen, but they find that this insistdifferent ontogenetic histories of closely allied forms has led us ence on the individual, although invaluable from the to a much fuller conception of the mode in which stages in point of view of recording species, is unsatisfactory from the point embryonic and larval history have been modified in relation of view of scientific zoology; and propositions for the ameliorato their surroundings, and to a consequent reluctance to attach tion of this condition of affairs range from a refusal of Linnaean detailed importance to the embryological argument for evolution. nomenclature in such cases, to the institution of a division The vast bulk of botanical and zoological work on living and between master species for such species as have been properly extinct forms published during the last quarter of the 19th revised by the comparative morphologist, and provisional species century increased almost beyond all expectation the for such species as have been provisionally registered by those Phylogeny. evidence for the fact of evolution. The discovery of working at collections. Those who work with living forms of a single fossil creature in a geological stratum of a wrong period, which it is possible to obtain a large number of specimens, and the detection of a single anatomical or physiological fact irrecon- those who make revisions of the provisional species of palaeontocilable with origin by descent with modification, would have been logists, are slowly coming to some such conception as that a destructive of the theory and would have made the reputation species is the abstract central point around which a group of of the observer. But in the prodigious number of supporting variations oscillate, and that the peripheral oscillations of one discoveries that have been made no single negative factor has species may even overlap those of an allied species. It is plain appeared, and the evolution from their predecessors of the that we have moved far from the connotation and denotation forms of life existing now or at any other period must be taken of the word species at the time when Darwin began to discuss the as proved. It is necessary to notice, however, that although origin of species, and that the movement, on the one hand, tends the general course of the stream of life is certain, there is not the to simplify the problem philosophically, and, on the other, to same certainty as to the actual individual pedigrees of the make it difficult for the amateur theorist. existing forms. In the attempts to place existing creatures in approximately phylogenetic order, a striking change, due to a more logical consideration of the process of evolution, has become established and is already resolving many of the earlier difficulties and banishing from the more recent tables the numerous hypothetical intermediate forms so familiar in the older phylogenetic The older method was to attempt the comparison between the highest member of a lower group and the lowest member of a higher group-to suppose, for example, that the gorilla and the chimpanzee, the highest members of the apes, were the existing representatives of the ancestors of man and to compare these forms with the lowest members of the human race. comparison is necessarily illogical, as the existing apes are separated from the common ancestor by at least as large a number of generations as separate it from any of the forms of existing In the natural process of growth, the gap must necessarily be wider between the summits of the twigs than lower down, and, instead of imagining "missing links," it is necessary to trace each separate branch as low down as possible, and to institute the comparisons between the lowest points that can be reached. The method is simply the logical result of the fact that every existing form of life stands at the summit of a long branch of the whole tree of life. A due consideration of it leads to the curious paradox that if any two animals be compared, the zoologically lower will be separated from the common ancestor by a larger number of generations, since, on the average, sexual maturity is reached more quickly by the lower form. Naturally very many other factors have to be considered, but this alone is a sufficient reason to restrain attempts to place existing forms in linear phylogenetic series. In embryology the method finds its expression in the limitation of comparisons to the corresponding stages of low and high forms and the exclusion of the comparisons between the adult stages of low forms and the embryonic stages of higher forms. Another expression of the same method, due to Cope, and specially valuable to the taxonomist, is that when the relationship between orders is being considered, characters of subordinal rank must be neglected. It must not be supposed that earlier writers all neglected this method, or still less that all writers now employ it, but merely that formerly it was frequently overlooked by the best writers, and now is neglected only by the worst. The result is, on the one hand, a clearing away of much fantastic phylogeny, on the other, an enormous reduction of the supposed gaps between groups. There has been a renewed activity in the study of existing forms from the point of view of obtaining evidence as to the nature and origin of species. Comparative anatomists have been learning to refrain from basing the diagnosis of a species, or the

man.

Such a

The conception of evolution is being applied more rigidly to the comparative anatomy of organs and systems of organs. When a series of the modifications of an anatomical structure has been sufficiently examined, it is frequently possible to decide that one particular condition is primitive, ancestral or central, and that the other conditions have been derived from it. Such a condition has been termed, with regard to the group of animals or plants the organs of which are being studied, archecentric. The possession of the character in the archecentric condition in (say) two of the members of the group does not indicate that these two members are more nearly related to one another than they are to other members of the group; the archecentric condition is part of the common heritage of all the members of the group, and may be retained by any. On the other hand, when the ancestral condition is modified, it may be regarded as having moved outwards along some radius from the archecentric condition. Such modified conditions have been termed apocentric. It is obvious that the mere apocentricity of a character can be no guide to the affinities of its possessor. It is necessary to determine if the modification be a simple change that might have occurred in independent cases, in fact if it be a multiradial apocentricity, or if it involved intricate and precisely combined anatomical changes that we could not expect to occur twice independently; that is to say, if it be a uniradial apocentricity. Multiradial apocentricities lie at the root of many of the phenomena that have been grouped under the designation convergence. Especially in the case of manifest adaptations, organs possessed by creatures far apart genealogically may be moulded into conditions that are extremely alike. Sir E. Ray Lankester's term, homoplasy, has passed into currency as designating such cases where different genetic material has been pressed by similar conditions into similar moulds. These may be called heterogeneous homoplasies, but it is necessary to recognize the existence of homogeneous homoplasies, here called multiradial apocentricities. A complex apocentric modification of a kind which we cannot imagine to have been repeated independently, and which is to be designated as uniradial, frequently forms a new centre around which new diverging modifications are produced. With reference to any particular group of forms such a new centre of modification may be termed a metacentre, and it is plain that the archecentre of the whole group is a metacentre of the larger group of which the group under consideration is a branch. Thus, for instance, the archecentric condition of any Avian structure is a metacentre of the Sauropsidan stem. A form of apocentricity extremely common and often perplexing may be termed pseudo centric; in such a condition there is an apparent simplicity that

reveals its secondary nature by some small and apparently | which has been strongly reinforced from the side of physical meaningless complexity.

nomis.

more meaning to the results than from their nature they can bear. The ultimate value of numerical inquiries must depend on the equivalence of the units on which they are based. Many of the characters that up to the present have been dealt with by biometrical inquiry are obviously composite. The height or length of the arm of a human being, for instance, is the result of many factors, some inherent, some due to environment, and until these have been sifted out, numerical laws of inheritance or of correlation can have no more than an empirical value. The analysis of composite characters into their indivisible units and statistical inquiry into the behaviour of the units would seem to be a necessary part of biometric investigation, and one to which much further attention will have to be paid.

science, insists on quantitative measurements of the terms. Another group of investigations that seems to play an im- When the anatomist says that one race is characterized by long portant part in the future development of the theory of evolution heads, another by round heads, the biometricist demands numbers relates to the study of what is known as organic and percentages. When an orgán is stated to be variable, the Blo- symmetry. The differentiations of structure that char- biometricist demands statistics to show the range of the variaacterize animals and plants are being shown to be tions and the mode of their distribution. When a character is orderly and definite in many respects; the relations of the said to be favoured by natural selection, the biometricist demands various parts to one another and to the whole, the modes of investigation of the death-rate of individuals with or without repetition of parts, and the series of changes that occur in groups the character. When a character is said to be transmitted, or of repeated parts appear to be to a certain extent inevitable, to be correlated with another character, the biometricist declares to depend on the nature of the living material itself and on the the statement valueless without numerical estimations of the necessary conditions of its growth. Closely allied to the study inheritance or correlation. The subject is still so new, and its of symmetry is the study of the direct effect of the circumambient technical methods (see VARIATION AND SELECTION) have as media on embryonic young and adult stages of living beings yet spread so little beyond the group which is formulating and (see EMBRYOLOGY: Physiology; HEREDITY; and VARIATION defining them, that it is difficult to do more than guess at the AND SELECTION), and a still larger number of observers have importance of the results likely to be gained. Enough, however, added to our knowledge of these. It is impossible here to give has already been done to show the vast importance of the even a list of the names of the many observers who in recent method in grouping and codifying the empirical facts of life, times have made empirical study of the effects of growth-forces and in so preparing the way for the investigation of ultimate and of the symmetrical limitations and definitions of growth." causes." The chief pitfall appears to be the tendency to attach It is to be noticed, however, that, even after such phenomena have been properly grouped and designated under Greek names as laws of organic growth, they have not become explanations of the series of facts they correlate. Their importance in the theory of evolution is none the less very great. In the first place, they lessen the number of separate facts to be explained; in the second, they limit the field within which explanation must be sought, since, for instance, if a particular mode of repetition of parts occur in mosses, in flowering-plants, in beetles and in elephants, the seeker of ultimate explanations may exclude from the field of his inquiry all the conditions individual to these different organic forms, and confine himself only to what is common to all of them; that is to say, practically only the living material and its environment. The prosecution of such inquiries beginning to make unnecessary much in-ences in flora and fauna, which seemed to be functions of genious speculation of a kind that was prominent from 1880 to 1900; much futile effort has been wasted in the endeavour to find on Darwinian principles special "selection-values" for phenomena the universality of which places them outside the possibility of having relations with the particular conditions of particular organisms. On the other hand, many of those who have been specially successful in grouping diverse phenomena under empirical generalizations have erred logically in posing their generalizations against such a vera causa as the preservation of favoured individuals and races. The thirty years which followed the publication of the Origin of Species were characterized chiefly by anatomical and embryological work; since then there has been no diminution in anatomical and embryological enthusiasm, but many of the continually increasing body of investigators have turned again to bionomical work. 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 bicnomical investigators recalls the theories of Lamarck, and the name Neo-Lamarckism has been used of such a school of biologists, particularly active in America. The weakness of the NeoLamarckian view lies in its interpretation of heredity; its strength lies in its zealous study of the living world and the detection therein of proximate empirical laws, a strength shared by very many bionomical investigations, the authors of which would prefer to call themselves Darwinians, or to leave themselves without sectarian designation.

Biometrics.

Statistical inquiry into the facts of life has long been employed, and in particular Francis Galton, within the Darwinian period, has advocated its employment and developed its methods. Within quite recent years, however, a special school has arisen with the main object of treating the processes of evolution quantitatively. Here it is right to speak of Karl Pearson as a pioneer of notable importance. It has been the habit of biologists to use the terms variation, selection, elimination, correlation and so forth, vaguely; the new school,

It is well known that Darwin was deeply impressed by differlocality, and not the result of obvious dissimilarities of Segrega environment. A. R. Wallace's studies of island life, toa. and the work of many different observers on local races of animals and plants, marine, fluviatile and terrestrial, have brought about a conception of segregation as apart from differences of environment as being one of the factors in the differentiation of living forms. The segregation may be geographical, or may be the result of preferential mating, or of seasonal mating, and its effects plainly can be made no more of than proximate or empirical laws of differentiation, of great importance in codifying and simplifying the facts to be explained. The minute attention paid by modern systematists to the exact localities of subspecies and races is bringing together a vast store of facts which will throw further light on the problem of segregation, but the difficulty of utilizing these facts is increased by an unfortunate tendency to make locality itself one of the diagnostic characters.

Bathmism.

Consideration of phylogenetic series, especially from the palaeontological side, has led many writers to the conception that there is something of the nature of a growth-force inherent in organisms and tending inevitably towards divergent evolution. It is suggested that even in the absence of modification produced by any possible Darwinian or Lamarckian factors, that even in a neutral environment, divergent evolution of some kind would have occurred. The conception is necessarily somewhat hazy, but the words bathmism and bathmic Evolution have been employed by a number of writers for some such conception. Closely connected with it, and probably underlying many of the facts which have led to it, is a more definite group of ideas that may be brought together under the phrase " phylogenetic limitation of variation." In its simplest form, this phrase implies such an obvious fact as that whatever be the future development of, say, existing cockroaches, it will be on lines determined by the present structure of these creatures. In a more general way, the phrase implies that at each successive branching of the tree of life, the branches become more specialized,

1

more defined, and, in a sense, more limited. The full implications | exists. Evora is of little commercial importance, except as an of the group of ideas require, and are likely to receive, much agricultural centre, but its neighbourhood is famous for its mules attention in the immediate future of biological investigation, and abounds in cork-woods; there are also mines of iron, copper, but it is enough at present to point out that until the more and asbestos and marble quarries. obvious lines of inquiry have been opened out much more fully, we cannot be in a position to guess at the existence of a residuum, for which such a metaphysical conception as bathmism would serve even as a convenient disguise for ignorance.

Darnley (c. 1365-1429), the commander of his Scottish body- | guard, who in 1423 had received the seigniory of Aubigny and in February 1427/8 was granted the right to quarter the royal arms of France for his victories over the English (see Lady Elizabeth Cust, Account of the Stuarts of Aubigny in France, 1422-1672, 1891). On Stuart's death (before Orleans during an attack on an English convoy) the countship reverted to the crown. It was again temporarily alienated (1569-1584) as an appanage for Francis, duke of Anjou, and in 1651 was finally made over to Frédéric Maurice de la Tour d'Auvergne, duke of Bouillon, in exchange for the principality of Sedan.

fearlessness. As a teacher he had a remarkable power of kindling
enthusiasm; and he sent out many distinguished pupils, among
whom may be mentioned Hitzig, Schrader, Nöldeke, Diestel
and Dillmann. His disciples were not all of one school, but many
eminent scholars who apparently have been untouched by his
influence have in fact developed some of the many ideas which he
suggested. His numerous writings, from 1823 onwards, were
the reservoirs in which the entire energy of a life was stored.
His Hebrew Grammar inaugurated a new era in biblical philology.
All subsequent works in that department have been avowedly
based on his, and to him will always belong the honour of having
been, as Hitzig has called him, "the second founder of the
science of the Hebrew language." As an exegete and biblical critic
no less than as a grammarian he has left his abiding mark. His
Geschichte des Volkes Israel, the result of thirty years' labour,
was epoch-making in that branch of research. While in every line
it bears the marks of intense individuality, it is at the same time
a product highly characteristic of the age, and even of the decade,
in which it appeared. If it is obviously the outcome of immense
learning on the part of its author, it is no less manifestly the
result of the speculations and researches of many laborious
predecessors in all departments of history, theology and philo.
race, which Lessing and Herder had made so familiar to the
modern mind, and firmly believing that to each of the leading
nations of antiquity a special task had been providentially
assigned, Ewald felt no difficulty about Israel's place in universal
history, or about the problem which that race had been called
upon to solve. The history of Israel, according to him, is simply
the history of the manner in which the one true religion really
and truly came into the possession of mankind. Other nations,
indeed, had attempted the highest problems in religion; but
Israel alone, in the providence of God, had succeeded, for Israel
alone had been inspired. Such is the supreme meaning of that
national history which began with the exodus and culminated
(at the same time virtually terminating) in the appearing of
Christ. The historical interval that separated these two events is
treated as naturally dividing itself into three great periods,
-those of Moses, David and Ezra. The periods are externally
indicated by the successive names by which the chosen people
were called-Hebrews, Israelites, Jews. The events prior to
the exodus are relegated by Ewald to a preliminary chapter of
primitive history; and the events of the apostolic and post-
apostolic age are treated as a kind of appendix. The entire con-
struction of the history is based, as has already been said, on a
critical examination and chronological arrangement of the
available documents. So far as the results of criticism are still
uncertain with regard to the age and authorship of any of these,
Ewald's conclusions must of course be regarded as unsatisfactory.
But his work remains a storehouse of learning and is increasingly
recognized as a work of rare genius.

EWALD, GEORG HEINRICH AUGUST VON (1803-1875), German Orientalist and theologian, was born on the 16th of November 1803 at Göttingen, where his father was a linenweaver. In 1815 he was sent to the gymnasium, and in 1820 he entered the university of his native town, where under J. G. Eichhorn and T. C. Tychsen he devoted himself specially to the study of Oriental languages. At the close of his academical career in 1823 he was appointed to a mastership in the gymnasium at Wolfenbüttel, and made a study of the Oriental manuscripts in the Wolfenbüttel library. But in the spring of 1824 he was recalled to Göttingen as repetent, or theological tutor, and in 1827 (the year of Eichhorn's death) he became professor extra-sophy. Taking up the idea of a divine education of the human ordinarius in philosophy and lecturer in Old Testament exegesis. In 1831 he was promoted to the position of professor ordinarius in philosophy; in 1833 he became a member of the Royal Scientific Society, and in 1835, after Tychsen's death, he entered the faculty of theology, taking the chair of Oriental languages. Two years later occurred the first important episode in his studious life. In 1837, on the 18th of November, along with six of his colleagues he signed a formal protest against the action of King Ernst August (duke of Cumberland) in abolishing the liberal constitution of 1833, which had been granted to the Hanoverians by his predecessor William IV. This bold procedure of the seven professors led to their speedy expulsion from the university (14th December). Early in 1838 Ewald received a call to Tübingen, and there for upwards of ten years he held a chair as professor ordinarius, first in philosophy and afterwards, from 1841, in theology. To this period belong some of his most important works, and also the commencement of his bitter feud with F. C. Baur and the Tübingen school. In 1847, "the great shipwreck-year in Germany," as he has called it, he was invited back to Göttingen on honourable terms-the liberal constitution having been restored. He gladly accepted the invitation. In 1862-1863 he took an active part in a movement for reform within the Hanoverian Church, and he was a member of the synod which passed the new constitution. He had an important share also in the formation of the Protestantenverein, or Protestant association, in September 1863. But the chief crisis in his life arose out of the political events of 1866. His loyalty to King George (son of Ernst August) would not permit him to take the oath of allegiance to the victorious king of Prussia, and he was therefore placed on the retired list, though with the full amount of his salary as pension. Perhaps even this degree of severity might have been held by the Prussian authorities to be unnecessary, had Ewald been less exasperating in his language. The violent tone of some of his printed manifestoes about this time, especially of his Lob des Königs u. des Volkes, led to his being deprived of the venia legendi (1868) and also to a criminal process, which, however, resulted in his acquittal (May 1869). Then, and on two subsequent occasions, he was returned by the city of Hanover as a member of the North German and German parliaments. In June 1874 he was found guilty of a libel on Prince Bismarck, whom he had compared to Frederick II. in "his unrighteous war with Austria and his ruination of religion and morality," to Napoleon III. in his way of "picking out the best time possible for robbery and plunder." For this offence he was sentenced to undergo three weeks' imprisonment. He died in his 72nd year of heart disease on the 4th of May 1875.

Ewald was no common man. In his public life he displayed many noble characteristics, perfect simplicity and sincerity, intense moral earnestness, sturdy independence, absolute

Of his works the more important are:-Die Composition der Genesis kritisch untersucht (1823), an acute and able attempt to account for the use of the two names of God without recourse to the document-hypothesis; he was not himself, however, permanently convinced by it; De metris carminum Arabicorum (1825); Das Hohelied Salomo's übersetzt u. erklärt (1826; 3rd ed., 1866); Kritische Grammatik der hebr. Sprache (1827)-this afterwards became the Ausführliches Lehrbuch der hebr. Sprache (8th ed., 1870); and it was followed by the Hebr. Sprachlehre für Anfanger (4th ed., 1874): Über einige ältere Sanskritmetra (1827); Liber Vakedii de Mesopotamiae expugnatae historia (1827); Commentarius in Apocalypsin Johannis (1828); Abhandlungen zur biblischen u. orientalischen Literatur (1832); Grammatica critica linguae Arabicae (1831-1833); Die poetischen Bücher des alten Bundes (1835-1837, 3rd ed., 18661867); Die Propheten des alten Bundes (1840-1841, 2nd ed., 18671868); Geschichte des Volkes Israel (1843-1859, 3rd ed., 1864–1868); Alterthümer Israels (1848); Die drei ersten Evangelien übersetzt u. erklart (1850); Über das äthiopische Buch Henoch (1854): Die Sendschreiben des Apostels Paulus übersetzt u. erklärt (1857); Die Johanneischen Schriften übersetzt u. erklärt (1861-1862); Über das vierte Esrabuch (1863); Sieben Sendschreiben des neuen Bundes (1870); Das Sendschreiben an die Hebraer u. Jakobos' Rundschreiben (1870); Die Lehre der Bibel von Gott, oder Theologie des alten u. neuen Bundes (1871-1875). The Jahrbucher der biblischen Wissenschaft (1849-1865) were edited, and for the most part written, by him. He was the chief promoter of the Zeitschrift für die Kunde des