Herdic

[From Peter Herdic, the inventor.] A two or four-wheeled carriage, or omnibus, having a lowhung body, with side seats and an entrance at the rear. Heredity, n. ( Biol.) The fact has long been recognized that the offspring of every animal and plant displays the general characteristics of its parents; and this established fact forms the basis of all systems of cla ification. From this has arisen the doctrine of the immutability of species, one which has recently been vigorously attacked, on the ground that the resemblance to parents is never complete, and that the slight deviations which occur may accumulate till they become sufficiently decided to constitute a new species. Two principles are therefore recognized: the one of resemblance, ascribed to the influence of hereditary descent; the other of variation, due to causes not as yet known. The resemblance of children to their parents is a fact of general observation, this going in most cases much beyond the mere likene of members of the same species, and including many special marks and traits. Occasionally the resemblance is so close that a child and one of its parents are scarcely distinguishable except through difference in age. Usually it is le close, but the cases are rare in which some degree of resemblance to one or both does not exist. Hereditary resemblance, as generally observed, is of external structure, and may embrace likene in feature, complexion, size and shape, and many minor bodily peculiarities. Even anomalies of structure are hereditarily transmitted, as in the case of six fingers and toes, have been sent down through four generations, and were probably swamped out in the end by intermarriage with normal mates. Heredity in internal structure is no doubt as common, though le apparent. In some families, for instance, the blood ve els have a large development, while in others they are small. The same may occur with the nervous and muscular systems. Tendency to certain diseases is also often transmitted; fecundity, length of life, ., may be inherited, and idiosyncracies of character frequently reappear in descendants. As one instance, may be mentioned the fact that in the Turgot family the fifty-ninth year was rarely pa ed, the members of the family usually failing in strength and dying at or before that age. In other families long life seems a hereditary characteristic. These are but a few instances of heredity which might be very widely added to. Many examples might be given of transmi ion of mental traits; and superior intellectual powers are certainly to some extent transmi ible, there being long lists of poets, painters, musicians, ., whose faculty descended through two or more generations. The tendency to commit suicide has been traced through four generations, and lunacy through eight or more generations. As for the charac teristics of human races, they remain intact through whole nations. Chinese parents, for instance, bear children who are never likely to be mistaken for other than Chinese. Each race displays this persistence, and has bred true through long continued generations. A child, however, cannot resemble both parents, where these differ considerably. In the case of hermaphrodite animals, the offspring very closely resem bles the single parent; but in the ordinary case of dual parentage there may be a close resemblance to one or the other parent, or an intermediate mingling of characters, in which case there will be a close resemblance to neither. In other cases & reversional heredity appears, the resemblance of the child being to a grandparent or some more distant ancestor. Occasionally indirect heredity appears, the resemblance being to an uncle, aunt, . Such an instance seems puzzling, but the explanation may be that both have derived their characters from a common ancestor. In some instances characters traceable to a very remote ancestor have appeared. These cases seem to indicate a partial arrest of development. The reason that heredity does not produce still more striking results lies in the fact that it is subject to a constant reversing influence, that of the tendency to vary, there being some principle of variation, whose cause is far from being understood, at work in all organic beings, producing some degree of change in every instance and occasionally highly marked changes. This cause, whatever its origin, seems to act upon the new being in the germ-probably upon the germinal cells of both parents-yielding a tendency to diverge in various characters. The result is that the offspring often bears only a distant resemblance to either of the parents, the divergence occasionally being very considerable. Parents of usual size, for example, may bear giants or dwarfs for children. Hare lip, polydactylism, ., appear as exceptions, though they may become transmi ible. Edward Lambert, the "porcupine man" (his whole body was covered with horny excrescences), was born of normal parents, though his peculiarity was transmitted through five generations. Minor exceptions are of daily occurrence. That these variations are due to some influence exerted upon the individual germ cells seems evident from the case of twins. These often bear a strong resemblance, yet occasionally present marked physical and mental differences. Yet the conditions of gestation were exactly the same and the variation must have had its origin in the reproductive cells, probably before the proce of fertilization took place. Some influence exerted from the organism or from external nature, some peculiarity of arrangement of the cell molecules and energies, some effect of a struggle for existence between the many germinal cells, or still more subtle influences, may produce this result, whose causes as yet lie out of scientific sight and reach. The differentiation appears even in twins joined by some connecting link. Thus in the case of Ritta and Christina, the joined twins of Presburg, one was handsome, gentle and sedate, the other ugly and quarrelsome. Chang and Eng, the Siamese twins, also presented differences, though not so great ones, of appearance and character. Study of organic nature leads to the conclusion that in the conflict between these two forces, that of heredity is the stronger. Individuals constantly diverge from the average characters of the race, yet the diver gence rarely becomes great, and soon disappears in their descendants, the race characters being remarkably per sistent. This is largely due, no doubt, to the unrestricted sexual union of persons of every condition of organization, with the result that divergence in one direction is soon balanced by divergence in the opposite, and the general average of conditions maintained; any marked divergence being soon swamped out by the influence of intermarriage. It is interesting to find that this is not the case among domesticated animals where selective breeding is pursued. In such cases individuals of new breeds are mated with each other, the swamping effects of promiscuous intercourse is prevented, and any divergence that appears can be retained, while by a continued selective breeding of new varieties results The American Dictionary and Cyclopedia may be produced differing widely from the race characters. The numerous widely differing breeds of dogs, pigeons, ., are cases in point. The same may take place, to a le er degree, in man. The separation of a people into castes or distinct cla es acts as a sort of in and-in breeding, and yields marked human varieties. A nation has often in the past become isolated from other nations of the same race, and in consequence gained persistent traits which might be considered as those of special human breeds. The Greeks and Romans, for instance, seem to have been very closely related, yet were markedly distinct in intellectual character and physical appearance. The Hindus, a cousin race, presented other national characteristics, and the same may be said of the Celts, Germans and Ru ians. All these descended from a single ancestral race, but subsequent isolation seems to have produced selective action, each tribe varying in a manner different from that of others, perhaps through some influence of nature. It may be that heredity acts more vigorously on the body than on the mind. The child receives the whole body from its parents. Of its mind it receives only the germ. The mental stores are gathered later, and though they are influenced by the hereditary mental strain, may be of a character to strongly modify this strain. Yet the inherent mental tendencies are very vigorous, and yield but slowly to transforming influences. In conclusion, it may be said that the influence of heredity on organic beings, while probably the most powerful of organic agencies, is not all-powerful, but is opposed by several reversing influences, whose effect is to yield breeds, varieties and races, and, as many maintain, organic species, genera and families. A principal cause of these divergencies is an innate principle of variation, whose origin and mode of action are obscure. Other causes are the mating of unlike individuals, and the influence of natural influences and education on the body and mind of the child, which may modify his whole nature and prepare him for the transmi ion of new characters to his descendants. In the view of modern evolutionists, the agencies referred to in this article are those which, acting during long periods on organic forms, have caused the vast divergencies which we perceive, while at the same time giving a strong and long continued persistence to family and race characteristics. Organic substances and mental conditions are to a considerable extent plastic, and seem to have been molded by nature's hands into an extraordinary variety of forms, while presenting an active opposing force of heredity which has prevented modifying influences from being too rapid in action and extreme in results. Heri (a're), or Huri, a river of Central Asia, having its source in the Hindoo-Coosh Mountains, 150 m. W. of Cabul, and pa ing through Afghanistan and Turkestan, terminates in the mora of Tejend, 150 m. E. of the Caspian Sea, after a course, N. and N.W., of 550 m. The city of Herat is situated on its banks.