HEREDITY.

New Zealand Herald, Volume XVII, Issue 5944, 4 December 1880, Page 6

HEREDITY.

The following ia the first portion of the paper on Heredity, read at the meeting of the Auckland Institute on November 15, by Mr. E. A. Mackeehnie, solicitor: —

Most of you will probably remember having seen in the London Punch for April last, twopictures touching upon this science, as I shall call it throughout my paper. One represents a comical-looking youth, upbraiding his parents for bringing such an extraordinary animal into the world; the other, the proposed union between those who had highly developed brain power, with those who had developed muscles to the neglect of brain. I refer to these drolleries simply to point out that the subject must have received considerable public attention before it could furnish food for mirth in the columns of a comic paper, devoted to the passing events and topics of the day. In truth, so far as I can learn, the science has of late created a good deal of interest in the public mind, and is treated generally, not with trilling or flippant levity, but with the seriousness befitting its admitted importance. The daily Press occasionally refers to its progress in some forcible and well written article or review : though the the subject itself, like other scientific subjects, is not well adapted to the ordinary newspaper reader—"it is caviare to the many." it figures, however, frequently in magazine articles of the day, and lecturers eagerly seize on it as presenting an opening likely to awaken attention and rouse the curiosity of their hearers. From all this I am led to believe that the science has during the last fewyeais been brought prominently before the public in a variety of ways, and that it is now well thought of and to some extent studied. No one has followed up inquiries into the facts supporting the science with greater persistence and ability than Mr. Francis (ialton. He has made known his theories, and stated very fully the evidence on which he relies in support of them in his work called " Hereditary Genius : An Inquiry into its Laws and Consequences." I propose to-night to direct your attention to some of those laws or consequences as stated by Mr. Galton, as I think they will interest you ; but I shall do so very briefly indeed, for the book is in the library of the Institute, anil can be referred to by any one desirous of further pursuing the study. "Man's natural abilities,"' says Mr. Galton"—and this is the key-note of the whole science—"are derived by inheritance, under exactly the same limitations as are the forms and physical features of the whole organic world." In support of this position he gives a variety of illustrations taken from the mode in which we treat animals under domestication. He shows clearly that whatever quality or peculiarity it is desired to develope or improve can readily be brought out by the breeder by judicious selection and treatment; and these qualities or peculiarities, once attained in the animal, can be established in an incredibly brief period so as to become a portion of its nature. There would appear to be no limit to man's power in this respect except the definite limit of the animal's own instincts and capacities, within the compass of which we must be content to work if we desire to alter and to vary. Many of us know from experience, but most from reading, how easy it ia to obtain a permanent breed of dogs, horses, or other animals gifted with peculiar powers and characteristics, by simply liclectini; and mating such as have the qualities we require and wish to reproduce and continue. A careful perusal of Darwin's "'Variation of Animals and Plants under I >..mextication," I think, will establish ti.i.-. And if this be so—if like begets like in .Kiimal natures of lower grade than our nv.n. the question may fairly be asked, why should not the rule apply with equal liiree to our own race? We have"pedigree .-tock of all kinds, pedigree wheat, and other cereals, and it would be strange indeed to find the law prevail in animal and vegetable life, and not in that paragon of animals—man. "It is quite practicable," says Mr. (ialton, "to produce a highly gifted race of men by judicious marriages during several consecutive generations,"—and this lie thinks he is able to prove. It would be dillieult, I think, to assign a valid reason why it should not be so. The organisation of the animal man dilTers but slightly from the organisation of animals in the scale immediately below him. The physical processus by which he originates are identical. The early stages of his formation are identical. The mode of his nutrition (before and after birth) is identical. " Compare, "says Professor Huxley, " the perfect structure of the adult man with theii structure, and a marvellous likeness of organisation is exhibited. He resembles them, as they resemble one another : he differs from them, as they dill'er from one another." And this statement, that there is a structural unity of man with thcrcstof the animal world appears horiiu outby observation, and is indeed admitted unreservedly by every student of comparative anatomy and osteology. But it is said the brain of a man dill'ers materially from the brain of all other animals, and therefore- what is true of them would not be. applicable to him. In some respects this undoubtedly is so, but anatomists and physiologists tell us the dill'creuce is only in its weight, si/.e, and complexity. As "in the apes, nature lias provided us with an almost complete series of gradations, from brains little higher than that of a rodent to brains little lower than that of man."' So we find in man brains representing every gradation of intelligence from the feeble powers of the simple diminutive brain to the enormous capacity of the complex and weighty. So far, therefore, as the brain is concerned, there is nothing to prevent the rule (if it exists) "that the ollspring generally, if not invariably, inherits the qualities of the parents," being'as applicable to man as to the lower animals, and the ruie would appear to include the mental as well as the physical qualities and attributes of the parents. " Mr. (ialtuu is not a believer in heavenborn genius as a thing apart from and out of the usual course of nature's workings. "Ability," he says, "does n,,t suddenly start into existence, or disappear with equal abruptness, but rather it rises in a gradual and regular curve out of the ordinary level of family life." i And this we can well conceive,' for it is entirely in keeping with all that we observe of nature's processes. Nature makes no violent leaps in her great progression, but passes by gentle gradations from step to step in the ascending scale—" from the formless to the formed—from the inorganic to the organic—from blind force to conscious intellect and will" -from the merest nerve fibre to the complex convolutions ot brain in the highest race of men. We are therefore disposed to credit his assertion as being in accordance with natural law when he states that "the statistics show that there is a regular average increase of ability m the generations that precede its culmination, and as regular a decrease in those that .succeed it. In the first case the marriages have been consentient to its production, in the latter they have been incapable of preserving it." In support of these views Mr. (ialton refers to a variety of classes or sck-L-ted bodies of men, one or'more of whose members has or have taken a prominent position in the world, and he attempts to prove by elaborate tables that all our most eminent men were either .sons of eminent men, or had relations who were, or became afterwards eminent. He takes the most eminent members of one hundred distinguished families, anil shows the percentage of eminent men in each degree of kinship to them. I'Yom these tables'wc learn that in relation tn those families there were eminent twenty-six fathers, thirty-sons, twentythree brothers, and a small percentage of other more remote kindred. He then enters into an examination of the career of men noted for mental ability in various pursuits in life The classes be has selected comprise the Judges of Kngland (between IGliO and ISO'.")), statesmen, English Peerages commaiidersOiavalaiidmilitaryJ.literarymeii, men of science, poets, musicians, painters, divines, and senior classics of Cambridge. He thus deals with no less than :!00 Umilies, containing between them llearly 1000 eminent men, of whom he considers 41". are illus. trious,

Kroin mental, >lr. CI niton turns to tlio consideration of physical powers, anil passes in review curtain f;unilies.;wliosu members have been eminent for great bodily strength and endurance —men who have been noted as oarsmen, wrestlers, boxers, and others. The same result follows —the same rule appears to hold good with them as with the mentally eminent. I'Yom these elaborate tables our race would appear to inherit the organisation, the tendencies, the aptitudes of their parents in ;i very marked degree indeed.

To this law there may be some exceptions. One illustration of the disturbing causes, explaining exceptions, must suffice, for I have time for no more. Others will suggest themselves readily to you. A child may inherit from both parents or from one only. If, for instance, one parent is musical and * Hurley's •' Man's Hacs in Nature;"

the other not, the child may be musical or insensible to music. In other cases the; influence of one parent may destroy that of the other ; and thus you will see an apparent exception may possibly confirm the general law. But if the good qualities of the parents descend to the otl'spring, the bad and objectionable ones with equal truth, must also be inherited. The weaknesses and diseases of parents probably are. We know this to be the case in many instances so far as diseases are concerned. We see whole families seamed and distorted with scrofula, and there is 110 trouble in tracing the disease through many generations of the same family. Parents suffering from disease of the heart, consumption, gout, or that terrible brain disease we call insanity generally transmit them to their children. Indeed, it may be said that all diseases arising from weak and defective organisation or impurity of blood are inherited. Children of drunkards, I believe, inherit a craving for alcohol. This is doubted by many, but to my mind it is clear, and I endeavoured to depict the mental agony and struggles of a human being so afflicted in his efforts to emancipate himself from the thraldom of such an inherited vice, in my paper on the American poet Edgar Poe read before the Institute a few months since. This disease, and others, such as gout, appear to be due to a vitiated state of the blood, and without au infusion of purer blood they cau neither be eradicated nor arrested. Docs not all this tally with the everyday experience of mankind ? Xo one expects healthy children from two scrofulous parents, or gentle natures from the violent and irascible, or men of genius from those who are idiots or of weak intellect. And if diseases and mental and physical weaknesses are thus inherited, so also, it is probable, are criminal propensities. It must, one would think, necessarily be so. Few of us can pass through life without being brought in contact with men in whom we re-

cognise a distinct criminal disposition. It is apparent in all they do. They indulge freely the base instincts and passions of their nature without restraint, and with no sense of shame or remorse. They may be detected and punished, or altogether escape the lash of our criminal law. But it is all one : they never alter. They are afflicted with a moral leprosy, and slink through the wnrld in scoundrel fashion, a very pest and pollution in the moral atmosphere. In many cases we are able to trace back the history of these men, and we not unfrequently find that their parents have been guilty of offences or crimes against society more or less continuous throughout their lives, and we must conclude if there is any truth in the science we are considering that these men have inherited a criminal nature, and belong to that large, well-defined, and easily recognised type of man, known to us as the criminal class. Nor if this be so, should it create any surprise, for if scrofula—a disease which is said to afVect tlie brain, predisposing to insanity—is inherited (as undoubtedly it is so far as I can learn) it is probable criminal propensities will be transmitted from parent to offspring with equal certainty. Mr. Galton in his chapter on the "Influences that effect the natural ability of nations," one of the most interesting in the book, makes some statements which not only interest, but afford abundant food for subsequent reflection and study. He ascribes the long period of the dark ages to (1) the enforced celibacy enjoined by religious orders on their votaries, and (2) to the persecution and destruction of the foremost men of the age. The social condition of the time, lie says, drove gentle natures —fitted for deeds of charity, meditation, the study of literature and art—into the bosom of the Church, and there they died calmly out. The blind persecution in that age, he further writes, brought thousands of the foremost thinkers of the period—men of special aptitude, fearless, truth-seeking, and intelligent—to the scaffold : or buried them in prison, or drove them into exile. A nation thus destroying the noblest and best of her children, preserving alone the servile, the indifferent, and the stupid as parents of future generations—must degenerate. The necessary consequence follows : Human nature becomes demoralized, brutalized, and a, heavy pall of ignorance settles upon and holds it to the ground. Among othur illustrations, he gives that of the Spanish nation, and as we are all familiar with at least the outlines of her history, I offer it for your consideration. We all know that Spain at one period rose to a foremost rank anions European nations : that her fall has been very great, and that the depth of degradation to which she has been reduced has been marvellous. Her people still rank as an inferior race, and it will take years before she rises again tr> the level of other nations. What has been the cause of this dire calamity V Mr. (ialton says the wholesale destruction of the most noteworthy of her people, lie estimates that the Spanish nation was drained of her best blood at the rate of 1000 persons annually, for three centuries, between 1471 and 1781. "The actual data during those 300 years, lie says, are 32,000 burnt, 17,000 burnt in effigy (having died in prison or escaped from Spain), and -2!)1,000 condemned to various terms of imprisonment

and other penalties." We shudder at such a policy—such wholesale destruction—ami we discern plainly the penalty .Spain has paid by such wanton shedding of her liest blood in the deterioration of her people. It i.s the same as if a breeder had culled the best animals from his flock for the butcher, and bred from the refuse that remained. An inferior breed has been naturally the result. Kvery writer or observer of note has described the Spanish race of late, years in the same in variable terms—superstitious, unintelligent, proud, cruel, ignorant and unprincipled. •'Wherever," says Lord Brougham, "the. iron foot of the Spaniard has trod, then' all public happiness is instantly destroyed." [To liu continued". I