HEREDITY.

Auckland Star, Volume XXXIX, Issue 70, 21 March 1908, Page 10

HEREDITY.

* Principles of Heredity," by G. Archdall Reid, M.8., F.R.S.E. 1 volume. (Chapman and Hall, Ltd.)

(By RAKGATTRA.)

;-1 Since theipublicatior. ot Darwin's epochi! making " Origin of Species," the two n ; great theories of Heredity and Evolution a i have found many exponents, who have ti J accepted and discarded parts of each i- j other's hypotheses until they have suc- >-! ceeded in confusing the general reading f public, and many medical readers also, - as to what is, or is not, proven: as to s which theories and hypotheses are on , true bases, and which on false. f Both interested and general readers t have tried to gather from the mass of - evidence some firm threads - upon which to build a working theory 1 applicable to life, but through the 1 heated contests on the " transmission of r acquirements," the cause of " variations," . and the importance of " natural selec- . tion," compared with other methods for ; the causation of evolution, the generality i of people have a useless, hazy idea upon ) the most important question to the race -I—that of heredity. This confusion is in- [ creased by the loose use of definite scien- ; tific terms, and also by conflicting stater ments made by men in positions which . give weight to their opinions. A clear r working theory upon heredity and evolu- , tion has long been needed, and Dr. Archt dall Reid has come to the front wytk a clear, concise and fair treatise upon the principles of heredity, and has given to the thinking world a work of keen, spe- • eial and general interest, full of clear reasoning and plain statement of the laws of heredity deducted from the evolution of man against disease. Strange to say, this field has not been touched by other scientists, and doctors, though the material has lain ready to their hands, have had neither the time nor the requisite training for an exhaustive study of the subjejet. Dr. Reid draws his deductions from races and from racial results, as well as from man during several or many generations. A great part of the book is occupied with the examination of that bone of contention—the transmission of acquirements, upon which Lamarck based his once widely-accepted theory of evolution. After examining this theory of Lamarck, and Darwin's theory, which attributes evolution to natural selection, and t».e Bothwic. which attributes it to '"an inherent adaptive 'rowth-force," which demands the aid <j» discontinuous miracle, Dr. Reid makes a plain case for natural selection, and definitely states that the transmission of acquirements is not the cause of evolution, and has no effect upon the race —that man does not transmit to his offspring acquirements, e.g., characters Or traits lie acquires from the environment either before or after birth. He transmits what is inborn in hh\, and the power to make acquirements. Dr. Keid I finds that evolution is due to natural selection and spontaneous variation which is inborn in the germ plasm, and not the result of transmission of what a man acquires during life. He finds that the human race could not have evolved on its present lines if it had possessed the power to transmit acquirements, for had tliat been the case the millions of acquirements made individually by the race would have produced a race of abnormality out of touch with its environment. The pith or adequacy of natural selection lies in its power of selecting what is fitted to environment, so that if it is true, the transmission of acquirements must be impossible. He holds that variations only, arising spontaneously, are inherent in the gerniplasm and the power to make acquirements individually. Acquirements arc made individually and caused by stimulus (nourishment, use or exercise) or environment, but parental acquirements arc not transmitted to offspring, and variations are rarely caused by the direct action of the environment on the germplasm. The germ plasm is able to resist nearly all or all imlucnces oj its environment. J In the preface the author says his j work contains much that is new, but j claims little as his own but his theory of ! the " transmission of the power to acquire." The book awakens one's keen interest, and is written with a ■••erve and unconventional freshness, and lightened here and there by a delicate irony, and a. I kindly treatment of antagonistic thought. It has a happy, graceful yet straight to the point style, which irresistibly carries the reader through nearly 400 pages of heavy and intricate thought and reasoning. It is essentially original and written in plain language and technical terms easily understood by the general reader. The author addresses his book to medical men chiefly, and calls attention to the need for training the medical student in the laws of. heredity, as doctors, nwre than other branches of scientific men, have opportunities tor gathering data for the study of heredity in relation to disease and its effects racially. The public will find in " The Principles of Heredity " two matters of deep gene--1 ral interest—the discussion and definite settlement of the transmissinn or nontransmission of diseases and their effects, the immunity secured by natural selection; and racial degeneration, whether caused by transmission of acquirements or by the cessation of the action of selee- j tion by too easy conditions of living. The public cares little whether Darwin, ! or Lamark or Reid is right, but it careg | very strongly whether tuberculosis can | be transmitted from parent to offspring, I or not. or whether alcoholism will result; in degeneration of the offspring of alcohol- I i.sts, or not. Also, it is keenly interested j to know it'racial degeneration is brought) about by transmission of acquirements ; undesirable to the human being, or by the cessation of selection so that the unlit may survive in an improved environment. It cares immensely whether or no insanity is caused or increased by alcoholism, or by criminal or tuberculous ancestry. The first eight chapters deal with heredity and its laws, putting plainly before the reader proofs and arguments for and against conflicting theories. The eighth chapter sums up, and the next five deal with immunity to disease and the evolution undergone by man in every part of the world against particular diseases with which he comes in contact. The latter half of this work treats, with a fresh and frank touch, and clear, far seeing thought, the great pressing problems of the time—education past and present; disease and its eradication or alleviation, insanity,alcohol and temperance; religion, and its effect on races and childbirth. , Among the many points of interest in every chapter, bi3 conclusions on bi-par- ■ ental reproduction and regression, and I his recapitulation of the life liistory of the race in the life history of the mdi I vidual, and the origin of zymotic diseases and narcotics are intensely inter- \ esting. The chapters o*ft narcotics, tuber- i culosis, the mind of man, will draw the I attention of the ordinary reader, while j for those interested in the question of man. ajid his makers the book is a field of treasure.