December 7, 191 1] 



NATURE 



181 



placed so as to illuminate the interior of the gill 

 cavities, Dr. Caiman well says: "What function they 

 can discharge in this position seems beyond conjec- 

 ture." It is very interesting also to read of Platycuma 

 holti, which seems to feed on the deep-sea ooze, that 

 it has a coiled food-canal, a very rare condition in 

 Crustacea. Another kind of interest attaches to the 

 occurrence of some old-fashioned types, such as the 

 Eryonidea, in the great abysses. In an equally in- 

 structive manner the author deals with the crus- 

 taceans of the surface of the sea, of the fresh waters, 

 and of the drj- land. 



A chapter on crustaceans as parasites and mess- 

 mates is full of quaint things ; we read of a little 

 crab, Hapalocarcinns inarsupialis, in which the female 

 allows herself to be imprisoned within a cage or " gall " 

 of living coral; of ^Ielia tesselata, which carries a 

 sea-anemone in each claw and uses it as a living 

 weapon ; and of the extraordinary life-histories of some 

 of the parasitic forms. The contact of crustaceans 

 with human life is illustrated by the palatable lobsters 

 and crabs, shrimps and prawns, by the part which 

 minute forms play in the economy of the sea, by the 

 unique case of the species of Cyclops which is the 

 intermediate host of the guinea-worm, and by borers 

 like the gribble. A short account of Crustacea in the 

 past completes the book, apart from useful appendices 

 on collecting and on literature. 



In every respect Dr. Caiman's book is a success; 

 it is as instructive as it is interesting, as careful as 

 it is picturesque. It is an admirable introduction not 

 merely to Crustacea but to natural history. In con- 

 nection with a second edition, we venture to suggest 

 that the author should consider the advisability of 

 r.'.lding another twenty pages with tables helping the 

 student to identify the commoner British forms. This 

 seems all the more feasible when we notice the 

 numerous excellent illustrations of British forms with 

 which the book is already provided. But in the 

 meantime we offer the author our congratulations. 



THE NUTRITIONAL VALUE OF 

 INDIVIDUAL PROTEINS. 



"Kl OW that the composition of the various foodstuffs 

 ^^ is becoming better known, physiologists can 

 apply themselves with renewed vigour and greater 

 success to_ the problem of the part which each plays 

 in nutrition. In this relationship most interest 

 attaches to the proteins, and it is with this important 

 class of substances that Dr. Osborne and Dr. Mendel 

 have commenced what promises to be a most valuable 

 series of researches.' It has long been known that 

 gelatin is an insufficient food, and this fits in with 

 the absence of certain molecular groupings (tvrosine 

 and tryptophane) from its composition. More recent 

 experiments have shown that other " imperfect " pro- 

 teins—for instance, the zein of maize — are also im- 

 perfect from the nutritional point of view. There are, 

 however, great difficulties in carrying out investiga- 

 tions on the effect of administering the necessary nitro- 

 gen in the shape of a single protein. In order to 

 clirninate individual differences in animals, the ex- 

 periments must be numerous ; but perhaps the greatest 

 drawback of all is the fact that a monotonous diet in 

 itself produces distaste for food, so that the experi- 

 ment_ is usually brought to an end by the animals 

 refusing to take what is offered them after a com- 

 paratively short period of time. 



In the present experiments rats were selected as 

 the object of attack; they can be utilised in large 



' " Keedinc Kxperimenf; with Isolated Foo<l Substances " l',y I B" 

 Osborne and Lafayette B. Mendel, with the cooperation of Edna L. Ferry. 

 r^P- 5.3- (Published by the Carnegie Institution of W.-»shinKton, igir.) 



NO. 2iq;, VOL. 881 



nunibers, and, being small animals, a comparatively 

 limited supply of the purified protein will last a long 

 time. Whether the results obtained are applicable in 

 all details to other animals, man included, one feels a 

 little chary in deciding, the proverbial association of 

 mice and men being hardly sufficient grounds for sup- 

 posing that men and rats are exactly similar in meta- 

 bolic habits. The rat's span of life is much shorter 

 than that of the larger animals, its first vear corre- 

 sponding roughlv to the first thirty vears of a man's 

 life. 



The two American physiologists mentioned have, 

 however, been remarkably successful in avoiding 

 the bad effects of a monotonous diet; but whether 

 this was due to luck or to certain precautions they 

 took is not quite clear from their publication. Which- 

 ever explanation is the correct one, they succeeded in 

 keeping their animals alive for many months. They 

 record numerous experiments in which casein formed 

 the sole nitrogenous constituent of the dietary, and 

 the animals exhibited no sign of ill-health or loss of 

 weight. One animal lived for nearly a year on a 

 diet in which the only protein given was the glutenin 

 of wheat. 



The authors direct attention to a most important 

 point which is frequently neglected in such experi- 

 ments. The metabolism of a growing animal is a 

 different story from that of the adult. This is recog- 

 nised empirically by practical physicians; it is recog- 

 nised in the discussion which has taken place in the 

 daily Press and elsewhere on the nutritive value of the 

 different kinds of bread. But the reason for such a 

 belief is still in the region of the unknown. We have 

 no certain knowledge of what are the food con- 

 stituents, no doubt present in quite small quantities, 

 which are of special value in stimulating growth in 

 young animals. Drs. Osborne and Mendel quite 

 clearly see the problem, but so far they have not 

 solved it. Casein, the protein selected for their most 

 numerous experiments, is the principal protein of 

 milk, the most important of the foods taken by the 

 young; and yet they found that this dietary, given 

 to young rats, maintained their weight, but led to 

 little or no growth. 



If we believe the exaggerated statements in the ad- 

 vertisements of foods consisting of this protein freed 

 more or less completely from the other constituents 

 of milk, we should be led to think them extremely 

 valuable substitutes for the untreated article. Prac- 

 tical experience has shown that this is not the case, 

 and the careful experiments which have prompted 

 these rernarks have the most important practical 

 outcome in showing the danger of tampering with 

 this essential article in the dietary of infants. Any 

 attempt to "purify" it by removing constituents 

 which are quite as important as the protein, and may 

 be, from the health and growth point of view, even 

 more important, is fraught with peril to the public. 



W. D. H. 



WMVERSARY MEETING OF THE ROYAL 

 SOCIETY. 

 npHE anniversary meeting of ihr Royal Society was 

 ■*■ hold on November 30. when the report of the 

 council was read and Sir Archibald Geikie delivered 

 his presidential address. In the evening the anniver- 

 sary dinner was given in the Hotel Metropole, and 

 the speakers included Lord Justice Buckley, who 

 proposed the toast of the Royal Society, Lord .Alver- 

 stone (Lord Chief Justice), the Lord ^fayor, and Dr. 

 A. W. Ward (president of the British Academy). 



In response to an appeal from the council for funds 

 for the construction of additional buildings for nd- 



