NATURE 



241 



THURSDAY, NOVEMBER 29, 1917. 



ORGANISM AND ENVIRONMENT. 



Organism and Environment as illustrated by 

 the Physiology of Breathing. By Dr. J. S. 

 Haldane. Pp. xi+138. (New Haven: Yale 

 University Press ; London : Oxford University 

 Press, 1917.) Price 55. 6d. net. 



"PJR. HALDANE'S book is a record of four 

 ■*-^ public lectures delivered by him under the 

 Silliman Trust at Yale University in 1916. In 

 the short compass of httle more than a hundred 

 pages the author g-ives an admirable account of 

 the physiolog-y of breathing, based mainly on the 

 researches of himself and his pupils, which have 

 played so great a part in moulding our present 

 ideas on the subject. 



The special value of the book to students lies 

 in the fact that the function of respiration is 

 treated simply as one aspect of the activities of 

 the organism as a whole, as a chapter in the un- 

 ending series of adaptations, internal and ex- 

 ternal, which make up the life of an individual. 

 There is a real danger that, in the detailed ana- 

 lytical study of isolated phenomena and functions 

 which the student meets with in successive chap- 

 ters of any text-book of physiology, he may lose 

 sight of the essential unity of all the phenomena 

 presented by a living organism. 



The first lecture is devoted to the regulation of 

 respiration and the part played therein by chemical 

 and nervous factors. The second treats of the 

 readjustments of regulation in acclimatisation 

 and disease. After a description of the method 

 in which the hydrogen-Ion concentration of the 

 blood is regulated and the effects on the organism 

 of alterations in oxygen-tension, an account is 

 given of the Pike's Peak experiments. It will be 

 remembered that these experiments led to the 

 conclusion that under such conditions of stress 

 ■AS are met with at high altitudes, where there 

 is a chronic deficiency of oxygen, the taking up 

 of this gas by the blood is enhanced by the 

 activity of the epithelium of the lung alveoli, 

 which transfers the gas to the blood at a higher 

 tension than it possesses In the alveolar air. On 

 these experiments many physiologists are inclined 

 to reserve judgment until they have been con- 

 firmed and controlled by the use of different 

 methods, especially in view of the fact that earlier 

 experiments, which seemed to show the same 

 active intervention of the alveolar epithelium at 

 normal oxygen-tension, have been disproved by 

 Dr. Haldane himself. It is suggested that these 

 earlier results were obtained when the experi- 

 menters were in a condition of chronic CO poison- 

 ing, so that their alveolar epithelium had under- 

 gone the same acclimatisation as would be evoked 

 by a stay of some duration at high altitudes. 



The third lecture deals with the regulation of 

 the environment, internal and external. It is 

 pointed out that "the gross regulation of the cir- 

 NO. 2509, VOL. 100] 



culation is of such a nature as to keep the venous 

 gas-pressures nearly steady, while regulation of 

 breathing keeps the arterial gas-pressures nearly 

 steady." Emphasis is laid on the fact that, in the 

 regulation of the blood-flow, as of the respiration, 

 the determining factor is the metabolic activity 

 of the body as a whole. 



In the fourth lecture, which is entitled "Organic 

 Regulation as the Essence of Life : Inadequacy 

 of Mechanistic and Vitalistic Conceptions," the 

 results of the preceding lectures are used as a 

 text from which to expound the author's views as 

 to the methods and aims of physiology. He seems 

 herein to erect dummies, labelled " vitalist " and 

 "mechanist" respectively, for the pleasure later 

 of knocking them down. The reader would gather 

 from this chapter that physiologists were divided 

 into two camps, mechanistic and vitalistic. Is 

 this any more true than the statement, often made 

 by the layman, that the medical world is divided 

 into allopaths and homoeopaths? Is there funda- 

 mentally any difference in the point of view of 

 physiologists at the present day? All pursue 

 similar methods — the only methods which are open 

 to them — the careful observation of the phenomena 

 of living animals and the average sequence of 

 these phenomena. It is true that one finds among 

 physiologists, as among all other classes of 

 scientific men, the tendency to over-simplify, to 

 fit a new experience into a series which is already 

 familiar, while neglecting details which cannot be 

 so fitted in — an adjustment of facts to curves 

 rather than of curves to facts. But the opposite 

 danger is equally found. Workers, impressed by 

 the seeming impenetrability of the unknown just 

 in front of them, may give up too soon and yield 

 to the temptation of relegating to the arcana of 

 cell-activity processes which further research would 

 have shown to fall within a known category. This 

 faint-hearted attitude might be encouraged by a 

 sentence such as the following : " Those who seek 

 in physiological phenomena for the same kinds of 

 causal explanations as can usually be assigned 

 in connection with inorganic phenomena have no 

 prospect but to remain seeking indefinitely." This 

 prospect is common to all scientific workers, but 

 if the statement implies that no useful results can 

 be obtained in this way, it is not true. We can- 

 not claim to understand or to know fully even the 

 most familiar process in chemistry or physics, and 

 there is no question that further research will 

 considerably modify, what are now regarded as 

 fundamental principles— but are really working 

 schemata — in physics and chemistry. The ten- 

 dency of science is to make its formulae — its short- 

 hand of phenomenal sequence — more and more 

 wide-embracing. It is a dangerous thing, and 

 savouring of, dogma, to set bounds to this develop- 

 ment and to assume that the phenomena presented 

 by living beings, as well as those observed in so- 

 called Inanimate objects, may not in the future 

 be brought into some one great sequence or 

 natural law. 



The fact of consciousness will always remain 

 to remind each of us that all these laws are but 



O 



