November 30, 191 ij 



NATURE 



'57 



To the same author we are indebted fpr copies of two 

 papers on local crustaceans, pubhshed in vol. xliii. of the 

 iransactions of the New Zealand Institute. In the former 

 of these Mr. Chilton revises the New Zealand representa- 

 tives of the group (Stomatopoda) typified by the familiar 

 European Squilla mantis, while in the second he catalogues 

 the crustaceans at present known from the Kermadec 

 Islands. Despite the fact that the crustacean fauna of 

 those islands has been systematically collected, for the first 

 time no new forms are recorded. 



As the result of the examination of a collection of rotifers 

 ained from Clare Island, west coast of Ireland, Mr. 

 F. Rousselet (Proc. R. Irish Acad., vol. xxxi., p. 50) 

 Is that these organisms do not differ materially from 



'-e of the mainland. 



< )n the other hand, in a paper on Irish annelids of the 

 lily Maldanidae, Mr. I. Arwidsson iibid., vol. xxix., 

 ■.. B, p. 209) finds himself in a position to name and 

 cribe two new species, one of which is also regarded 

 "■ntitled to represent a new genus. 



In Bulletin No. 71 of the U.S. National Museum is 

 published the second part of Mr. J. A. Cushman's mono- 



r.ph of the Foraminifera of the North Pacific, this instal- 

 iit being devoted to the primitive family Textulariidae. 



,eral new species and a few new genera are described. 

 1 lie group has been found to be of considerable interest 

 from the distributional point of view. It is stated, for 



-tance, that " many of the species occurring in the Indo- 



cific area extend southward to the region of Torres Strait. 

 in the North Pacific, however, these species are, as a rule, 

 confined to the western portion from southern Japan 

 southward. The rediscovery of some of the species 

 di^scribed by J. Brady, from almost the exact locality where 

 they were dredged by the Challenger, is very interesting, 

 and tends to show the restricted distribution of certain 

 forms." 



Rotifers of the bdelloid group indigenous to South Africa 

 form the subject of an article, by Mr. J. Murray, in vol. iii., 

 No. I, of the Annals of the Transvaal Museum. Although 

 the Central and North African representatives of the group 

 had received some attention, very little was known with 

 regard to those of the South, so that the author has been 

 able to make considerable additions to our knowledge. The 

 paper concludes with a summary of what is known with 

 regard to African bdelloids generally. 



In vol. viii., Nos. 4-6, of the University of California 

 Zoological Papers Mr. C. A. Kofoid continues his account 

 of the dinoflagellate animalcules of the San Diego area, 

 dealing in the first two papers with the genus Gonyaulax 

 and the morphology of its skeleton, while in the third 

 (forming the fifth of the whole series) he describes, under 

 the name of Spiraulax, a new generic type of the peridinid 

 group. 



The nine species of earwigs now found in the British 

 Islands (some of which are introduced) form the subject of 

 ft coloured plate in the October number of The Entomo- 

 logist's Monthly Magazine. According to Dr. M. Burr, 

 nearly all thesf^ earwigs, with the exception of the common 

 species, are rare and local. R. L. 



A 



LIPOIDS AND NUTRITION. 



WORD is perhaps necessary in explanation of the 

 term lipoids. These are substances, contained in the 

 outer protoplasmic layer of all cells, which resemble the 

 fats in being soluble in organic solvents. They appear to 

 be essential constituents, and are specially abundant in that 

 tissue which pre-eminently manifests " vital properties," 

 namely, the nervous tissues. The majority of them, though 

 by no means all, contain both phosphorus and nitrogen. 

 Very little is as yet known as to their constitution and 

 properties. 



At the present moment, when so much attention is 

 being devoted to problems of nutrition, a communica- 

 tion by Prof. Stepp, of Giessen (in part v. of the Zeit- 

 schrift fiir Biologic), is of very considerable interest. The 

 idea has been gaining ground that an ordinary diet con- 

 tains certain constituents, present only in minimal 

 quantity, the presence of which, in addition to the proper 

 1 tportions of protein, carbohydrate and fat, is ess-entinl 



NO. 2196, VOL. 88] 



for growth and the maintenance of life. Experiments 

 made with rice in connection ~ with " beri-beri " have 

 pointed to such a conclusion ; and the work of Prof. 

 F. G. Hopkins, of Cambridge, of which, so far, only a 

 preliminary account has been given, has gone very much 

 further in the same direction. 



Prof. Stepp, who selected mice for his experiments, has 

 studied the effect of extracting the food very completely 

 with alcohol and ether before administration. The food 

 used consisted of a dried mixture of rice, treated so as to 

 be particularly rich in protein, and new milk ; before 

 extraction it was found to be a very satisfactory nutrient 

 for mice. When fed, however, with the extracted food, the 

 mice very soon died, showing that an essential constituent 

 had been extracted from the food. The addition of mineral 

 salts to the extracted food did not make it of any greater 

 value, but the addition, on the other hand, of the 

 evaporated extract enabled the mice to remain alive and 

 thrive. Extraction in the manner described removes, 

 amongst other things, fats from the diet. Accordingly, 

 experiments were made in which butter or fats such as 

 tripalmitin, tristearin, or triolein were added to the ex- 

 tracted food ; in no case was the addition of the faintest 

 value in preserving life. The essential substance is con- 

 sidered to be a lipoid which is absent from butter,- though 

 present in the milk plasma. In proof of this it is estab- 

 lished that an extract of dried butter-milk when added to 

 the extracted food is sufficient to keep the mice still in 

 good condition at the end of six weeks. It is possible to 

 measure the quantity of this lipoid required ; and the 

 experiments show that whereas the evaporated extract of 

 75 c.c. of milk per 100 grams of solid extracted food was 

 insufficient, that from 200 c.c. of milk was more than 

 enough to maintain health. 



Certain of the lipoids have been isolated in a pure state, 

 and their effect could be tested ; it was proved that the 

 addition of either lecithin or cholesterol to the diet was 

 of no use. The essential substance is therefore of a very 

 subtle character. Stepp 's experiments with boiled milk 

 are of some interest ; though boiled milk by itself is of 

 value to the animals, the alcoholic and ethereal extracts 

 of it when added to the extracted food are unable to main- 

 tain life. 



If these conclusions are substantiated, an altogether new 

 trend will be given to work on nutrition. 



WATER RESOURCES OF THE UNITED 

 STATES. 

 r~)F the three volumes recently issued by the United 

 ^-^ States Geological Survey, that (No. 256) on " The 

 Geology and Underground Waters of Southern Minnesota," 

 by Messrs. Hall, Meinger and Fuller, is certainly the most 

 interesting, and claims primary notice. It is a brochure 

 of 406 pages, with a number of sections and diagrams 

 and four folding maps, all descriptive of matters, physio- 

 graphical, geological, and chemical, connected with water 

 supplies in the southern two-fifths of the State of 

 Minnesota — an area of 28,265 square miles, which is 

 roughly about the size of Scotland or Ireland. The dis- 

 trict contains two towns of importance, Minneapolis and 

 St. Paul ; but, apart therefrom, the whole, with its 

 i^ million inhabitants, is essentially agricultural in 

 character. The surface comprises three elevated plateaus 

 of different levels, with trough-like depressions between, 

 all, with the exception of the extreme south-cast and south- 

 west corners, composed of glacial drift deposited during 

 the most recent ice invasion. " Nowhere is there a more 

 typical example of a ground moraine left in the wake of a 

 continental ice sheet than is exhibited by the extensive. 

 slightly undulating, monotonous expanses of southern 

 Minnesota, dotted with countless shallow lakes and ponds, 

 and covered with an interminable network of swamps." 



Generally speaking, the drift is yellowish at the surface 

 to a depth of some 15 feet, where it changes to a dark 

 colour, due, no doubt,' to the presence of unoxidised iron: 

 and the water contained in it is almost universally charged 

 with that mineral in the soluble ferrous condition. The 

 effect oT this, and of other constituents, on the utility and 

 value of the water for various purposes is discussed at 

 some length, and the volume then proceeds to deal with 



