444. 



NATURE 



[August 8, 191. 



species and varieties, Mendelism, and other sub- 

 jects inseparable from the main thesis. Part ii. 

 consists of concise summaries of the morphology 

 and reproduction of the hig-her plants, and in ! 

 part iii. some hypotheses are briefly considered ! 

 and summed up. in the following words:- — " Les ! 

 probl^mes sur revolution que soulfeve I'etude : 

 morphologique des vegetaux resteraient de j 

 creiises et inutiles discussions verbales si elles ne ] 

 devaient pas conduire k des experiences qui per- | 

 mettront sans doute un jour de comprendre cette i 

 evolution assez precis^ment pour la diriger. " | 

 *'The Evolution of Plants " is a familiar title, 1 

 allowing free play to an author's imagination : to ! 

 the layman it suggests a clear picture of the gra- j 

 dual development of plant-life from a speck of ' 

 living protoplasnj to an oak tree. The nearer a ! 

 book approaches to this standard of precision the 

 less value it has for the biologist. Bernard's book ! 

 is not of this class ; it is a serious contribution | 

 which should at least bring home to the layman 

 not only the difficulties of the problems discussed, 

 but also the extent of our ignor^ince of the lines 

 along which the development of the plant kingdom 

 has proceeded. A. C. S. 



Ambulance de " L'Ocian," La Panne. Tome i., 

 fasc. ii. Travaux publics sous la direction du 

 Dr. A. Depage. Secretaires de la Redaction: 

 Dr. A. P. Dustin, Dr. G. Debaisieux. Pp. 381. 

 (Paris: Masson et Cie, 1917-) 

 TtfE editor and publishers may be congratulated 

 on the attractive way in which this second number 

 of the "Travaux" of the "Ambulance de 

 ' L'Ocean '" at La Panne makes its appearance. 

 The papers are copiously illustrated with 

 beautifully executed figures. The researches 

 are naturally devoted to questi6ns concerning 

 the pathology and treatment of wounds . and 

 contain many valuable result's, which do not 

 admit of a brief account. The following may 

 be referred to as of more general scientific 

 interest, Depage a lid Ma^loens show that wounds 

 naturally tend to become sterile; the process, never- 

 theless, may be aided by the brief action of a 

 strong antiseptic. But prolonged action is injuri- 

 ous to the growing cells. The good effect of 

 Dakin's solution is said to be due chiefly to its 

 solvent action on exudations and dead tissue. Dustin 

 gives a valuable and complete account of the histo- 

 logical changes in injured nerves. De Harven 

 concludes that the choroid plexuses have a secre- 

 tory function. Sand brings evidence to show 

 that toxic products are produced by the disinte- 

 gration of injured muscular tissue, whether due 

 to mechanical action or to , bacterial infection. 

 Levaditi and Debrez give a detailed investigation 

 of the flora of wounds and of the physico-patho- 

 logical properties of exudations. Zunz was unable 

 to find " acidosis " (diminution of alkaline reserve) 

 in the blood of wounded men, unless bacterial in- 

 fection or respiratory obstruction was present. 

 Govaerts points out the importance of transfusion 

 of iblood at an early stage after haemorrhage. 

 Saline solutions were found useless, but^e effect 

 of the addition of gum was not tested. * 

 NO. 2545, VOL. lOl] 



LETTERS TO THE EDITOR. 

 [The Editor does not hold himself responsible for 

 opinions expressed by his correspondents. Neither' 

 can he undertake to return, or to correspond with 

 the writers of, rejected manuscripts intended for 

 this or any other part of Nature. No notice 15 

 taken of anonymous communications.] 



Medusoid Bells. 



Just now the sea is full of little tiny bells,' and, 

 what is more, they are all a-ringing. A few weeks 

 ago I watched some of them developing. Precisely 

 how they do so is not very easy to see, but thev 

 develop with amazing rapidity. It is hard indeed to 

 believe that they "grow," cell by cell; rather do they 

 seem just to "come off" the parent stock, one after 

 another, like little curiously formed drops or droplets. 

 They seem to me to be formed as a whole, and, 

 apf>arently (to use Adam Sedgwick's words, written 

 more than thirty years ago), whatever cellular 

 elements they contain "must be regarded as a multi- 

 plication of nuclei and a specialisation of tracts and 

 vacuoles in a continuous . mass of protoplasm." If 

 this be so, we may throw conventional embryologv 

 aside, and conceive of the little bell as being auto- 

 matically conformed by some physical process akin, 

 to the many beautiful phenomena of ordinary drops. 

 But let us pass this problem by for the moment, and 

 merely inquire what modifications of structure would 

 be likely to ensue if the little bell, once formed or 

 partly formed, were to be in a state of vibration; and 

 if at the same time its semi-fluid or colloid, and very 

 heterogeneous substance were such as to permit easy 

 transference from place to place of its heavier or 

 lighter particles. 



Suppose the little bell to vibrate as other bells do, 

 then its fundamental note will give us four marginal 

 nodes and four corresponding radial nodal lines. We 

 see the latter marked but in our .medusoid in the 

 form of four equidistant and exquisitely symmetrical 

 " radial canals " ; while at the marginal nodes there 

 appear little aggregations, sometimes of pigment,, 

 sometirnes of calcareous matter, which we call "eye- 

 spots" or "otoliths." The margin of the bell, if it be 

 free and thin, 'will tend to be thrown into secondary 

 vibrations, overtones of the fundamental note; and 

 these, as the substance firms, are rendered visible as 

 Tittle rounded lobes and notches set round the bell 

 with perfect symmetry. At the nodal points we mav 

 next anticipate that little portions or drops of quasi- 

 superfluous fluid might accumulate, and these would 

 gradually elongate into streamers or "liquid jets," and 

 would varv in form, remaining single or becoming: 

 branched, remaining smooth or becoming annulated 

 or beaded, according, to the surface-tensions between 

 their substance and the surrounding medium. In anv. 

 case, thev would agree in number and position with 

 the nodes, and where these were nUmerous and of 

 successive orders, so also would the tentacles tend to 

 correspond in order and magnitude. In short, several 

 of the most imnortant and most conspicuous features 

 of the little "bell" would follow from the simple hvpo- 

 f-hesls of its. intrinsic vibration. Fitzgerald and oth'^'-'^ 

 have suggested that we may, in like manner, ' ascribe 

 to vibration the minute and exquisite patterns of many 

 diatoms; Dendv and Nicholson have made use of the 

 same hypothesis to explain the characteristic form of 

 certain sponge-spicules. I have a strong idea that the 

 principle is very far-reaching indeed, and that its 

 bearing on morphological problems will be found to 

 be. of great importance. 



Our little medusoid is but a single instance, a single, 

 •tvpe, out of very many. .All through the Ccelenterata. 

 in polvpes and corals of all sorts, we are confronted 



