!28 



NA TURE 



[February i, 1906 



Although the cerebral hemispheres resemble those of the 

 carnivorous type, yet the frontal lobes are so singularly 

 under-developed that the author finds therein an explan- 

 ation of the relative stupidity of the dolphin. 



" Bidder's Organ " (Spengel) was discovered in 1758 by 

 Rosel von Rosenhof upon the testes of Bufo calamita. 

 Or. Attilio Cerruti, by means of material captured in the 

 volcanic crater of Archiagnano, near Naples, has been able 

 to demonstrate a highly interesting cytological process 

 which occurs in the male individuals of Bufo vulgaris 

 during the early months of the year. Certain of the cells, 

 named ovules, of the organ of Bidder are so strongly 

 attracted by some of their neighbours that they actually 

 penetrate (heir enveloping membranes, and their cytoplasm 

 and nuclei How into the invaded cells. In the majority of 

 cases the penetration is simple, i.e. only one ovule invades 

 a second, but multiple penetration has also been observed ; 

 and then in the case of ovules, say, a, b, <', ci, ovule a 

 will penetrale into b, b into c, c into d. Sec. In all cases 

 of penetration, degener.il ion ensues. Generally speaking, 

 the invading ovule is tin- younger, and is one which has 

 developed on the periphery of the organ, the invaded ovules 

 lying nearer the centre. The author draws a suggestive 

 comparison between this phenomenon and that of the fusion 

 of Ascaris ova described by O. zur Strassen, which, if they 

 develop at all, give rise to monsters. 



There are also four mathematical memoirs. Signor 



D. de Francesco contributes a paper on the motion of 

 a cord and on the equilibrium of a flexible but non- 

 extensible surface (Nos. 5 and (1, 5 pp., 9 pp.), and Prof. 



E, Cesaro investigates the intrinsic representation of a 

 surface (No. 7, zo pp.) and the curve of von Koch (No. 15, 

 12 pp.). A lengths contribution to the theory of ternary 

 biquadratic form and ils resolution into factors (No. J i, 

 102 pp.) is by the hand of Ernesto Pascal. 



R. T. G. 



PHYSIOLOGICAL ECONOMY IX NUTRITION. 



ANE of the most remarkable points in the recent history 

 ^-^ of physiological research is the small amount of atten- 

 tion bestowed upon the important question of nitrogenous 

 metabolism until within the last few years. The older 

 work of Voit and of Pfliiger has for long been regarded 

 as authoritative, in spite of the fact that these two observers 

 are not at one on many essential fads. They, however, 

 agree that proteid food is a most essential constituent of 

 our diet, and that a minimum allowance per diem of 

 about 100 grams, corresponding to 16 to 18 grams of 

 nitrogen, is necessary for the well-being and equilibrium 

 of the average adult human individual. A dietary con- 

 taining this amount of proteid or albuminous material 

 would not be regarded by the average meat-eating English- 

 man to be a very liberal one, and is frequently exceeded. 



So firmly rooted has this idea of a proteid minimum 

 intake of 100 grams become that not only is it stated as 

 an axiom in the majority of text-books, but it forms the 

 basis of dietaries prescribed by responsible Governments 

 for use on military service, &c. The doctrine that proteid 

 food is the most necessary of all foods is so thoroughly 

 ingrained, even upon the lay public, that in popular par- 

 lance the words nutritious and nitrogenous are almost 

 synonymous. This is a very dangerous mistake, for the 

 non-nitrogenous constituents of diet, the carbohydrates and 

 the fats, are equally necessary for the maintenance of 

 bodily heat and energy, and so are equally, though in a 

 somewhat different sense, to be regarded as nutritious. 

 An example of this erroneous way of regarding food is to 

 be seen in advertisements that meet the eye everywhere; 

 preparations of milk, for- instance, an- sold which contain 

 mainly the proteid matter of that fluid, and are vaunted as 

 containing all the nutritious elements, the other con- 

 stituents being looked upon as us, -less. As a matter of 

 fact, milk is of special value on account of the admixture 

 of tlie non-proteid with proteid material, in the concen- 

 tration camps which were established during the later 

 phases ol the South African War, such hardships as 

 occurred there were mainly due, not to lack of proteid 

 nutriment, for the standard of nitrogen was fully main- 

 tained, but to lack or scarcity of vegetables and other 

 sources of carbohydrate food. 



NO. 1892, VOL. 73] 



For some considerable time, certain experimenters in 

 Germany have striven to demolish the fetish of the irre- 

 ducible minimum of the 16 or 18 daily grams of nitrogen, 

 but their work has not attracted world-wide acknowledg- 

 ment ; the experiments thev recorded were either made for 

 too short a time or on too few people to be regarded as 

 epoch-making. 



It has been left to America to make the question one 

 of immediate and urgent attention, and I propose in this 

 article to bring the conclusions of these American investi- 

 gators before the readers of Nature. 



Prof. R. il. Chittenden, of Yale University, and Dr. 

 Otto F^olin, of Waverlev, Massachusetts, are the two 

 principal exponents of the new doctrine, and I propose to 

 deal with them in that order. 



The Work of Chittenden. 



Chittenden has been working at the subject for some 

 years, and the results of his labours are given in a volume 

 which will amply repay perusal entitled " Physiological 

 Economy in Nutrition" (New York: F. A. Stokes Co., 

 1904). A more popular exposition of his ideas has been 

 published in a recent number of the Century Illustrated 

 Monthly Magazine (October, 1905, p. 859 et seq.). 



The question was first brought to the notice of Prof. 

 Chittenden by Mr. Horace Fletcher, who states that he 

 cured himself of dvspeptic troubles by lessening his proteid 

 nutriment below what was regarded as the physiological 

 standard. He has started a propaganda on the subject 

 from the economic point of view, for proteid is the most 

 expensive of the articles of diet. One at once sees that 

 the question is not merely one for the student of science, 

 but is most important for the man in the street as well. 

 Owing, no doubt, to his lack of physiological knowledge, 

 Mr. Fletcher attributed the benefits he derived to a 

 thorough mastication of the comparatively small amount 

 of food he took. Mastication is, of course, of importance, 

 but it does not possess the superlative importance attributed 

 to it by Mr. Fletcher, and will not explain the results of 

 the experiments made by Chittenden and his fellow- 

 workers. 



The number to which I have already alluded (16 to 18 

 grams of nitrogen a day) is based roughly on the usual 

 diet of the meat-eating nations, and it is argued that habit 

 and instinct alike are safe guides in determining such a 

 number, and the effects of such a diet in the maintenance 

 of health and bodily equilibrium have been abundantly 

 proved through centuries of experience. It forms, as 

 already stated, the basis of the usuallv accepted dietaries 

 of Ranke and of Voit. 



In other nationalities, it is true, a different figure has 

 been arrived at, and the same argument of habit and 

 experience might equally well be used in its favour. Thus 

 in certain semi-civilised races the proportion of flesh food 

 is much larger, and in other races, again — and this is the 

 commoner variation — the proteid intake is less. We need, 

 however, only consider the second alternative, for one can 

 hardly suppose anyone will advocate a return to more 

 carnivorous habits. It is alleged that in such nationalities 

 as the Japanese, or in groups of people like vegetarians, 

 and in certain rural populations, health and equilibrium 

 are as well maintained as in the ordinary meat-eating 

 inhabitants of our large cities. Those who hold that the 

 number 16 to iS is the correct one have explained the 

 different number arrived at by the nations of the Far 

 East as a racial difference propagated by long centuries of 

 inheritance, or have tried, more or less successfully, to 

 show that such people come nearer 10 Voit's standard than 

 had been supposed, or else- that (hey are not properly 

 nourished. 



Such explanations will net hold water when applied 

 t < 1 tire experiments conducted by Prof. Chittenden upon 

 himself, his colleagues, his students, and upon a consider- 

 able number of athletes and soldiers. These experiments 

 lasted in all cases for munlhs, and in some for more than 

 a year. The proteid intake was reduced (o half, and in 

 sc.ine cases to less than hall the number hitherto regarded 

 as normal. After a variable' initial drop in body-weight,/ 

 (he deprivation was apparently followed by no untoward 

 results. Equilibrium was maintained ; the health remained 



