February 28, 19 18] 



NATURE 



517 



: 1 the usual three years' course at Oxford or Cam- 

 Ki idge University." — Sir Edward Wood, of Leicester, 

 who died on September 27 last, left 2000I. for a Sir 

 Edward Wood scholarship at the Wyggestoil Hospital 

 Schools for sons of parents who require assistance in 

 giving their sons a higher education. 



SOCIETIES AND ACADEMIES. 

 London. 

 Royal Society, February 14.— Sir J. J. Thomson, 

 president, in the chair.— Prof. E. W. MacBride ; The 

 I artificial production of Echinoderm larvae with two 

 aler-vascular systems, and also of larvae devoid of a 

 ler-vascular system. In Echinoderm larvae the 

 nge from bilateral to radial symmetry is due to a 

 ries of changes which are ushered in by the appear- 

 ce of a small bud, termed the hydrocoele, on the left 

 e of the larvae. This bud is the rudiment of the 

 ater-vascular system of the adult. A number of in- 

 nces have been recorded where, in an isolated speci- 

 len, a similar bud has appeared on the right side 

 Iso, and the whole later history of the larvae has been 

 Itered. The present communication describes a 

 ethod for inducing the formation of a second hydro- 

 le. By exposing the larvae to the action of hj-per- 

 tonic water at a certain critical period of their de- 

 velopment, and by removing them afterwards to ex- 

 tremely favourable surroundings, in so far as concerns 

 both food and space, it is possible to secure that a 

 certain percentage of them will possess two hydrocceles. 

 The development of the second hydrocoele may begin 

 earlier or later. If it begin earlier the organs found 

 in the normal larvae on the right side (pedicellarige) 

 will not be formed, but if it begin later one or more of 

 these organs may be formed. If larvae be starved for 

 ill'- first week of their existence and then transferred 

 -ood conditions as to food and space, the formation 

 l)Oth hydrocoele and pedicellariae will be inhibited, 

 i larvae perfectly bilaterally symmetrical will be pro- 

 pd which are provided on each side with a group 

 pointed spines in place of both hydrocoele and pedi- 

 iariae. From this observation it seems to follow 

 1 the formation of pedicellariae is dependent on the 

 jjicsence of a hydrocoele bud, so that this bud tends to 

 induce the formation of pedicellariae on the opposite 

 side of the larvae, and to inhibit their formation on 

 the same side as itself. The formation of a hydrocoele 

 bud on the right side involves profound modifications 

 of the surrounding tissues. These tissues are forced 

 to pursue a course of development totally foreign to 

 anything that has been normal in the history of the 

 race. In conclusion, the bearing of the facts adduced 

 on the nature of the laws governing the building up 

 of the bodies of embr3'os and larsae is discussed. — 

 Prof. J. B. Farmer : The quantitative differences in the 

 water-conductivity of the wood in trees and shrubs. 

 The paper deals with the efficiency of the wood re- 

 garded from the viewpoint of water-conductivity. 

 About sixty species of plants, chiefly trees and shrubs, 

 have been investigated. The method adopted consists 

 in determining the amount of water passing in fifteen 

 minutes, delivered at a head of 30 cm. of mercury- 

 through each square centimetre of wood of 15 cm. in 

 length. The results show that wide differences exist be- 

 tween different species, but that for a given species there 

 is commonlv an ascertainable mean. Evergreens as a 

 class are characterised bv wood of low conductivitv 

 with often small absolute fluctuation. Deciduous adult 

 trees and shrubs always possess wood of relatively high 

 conductivity, but the sapling trees and stool shoots of 

 coppiced woods exhibit low conductivity in their wood, 

 even when that of the adult shoots is high. The re- 

 sults are of significance in throwing lighten an aspect 



NO. 2522, VOL. 100] 



I of xerophily and of transpiration which has hitherto 

 i been disregarded. It is also shown that the dying 

 I back of the leaders in some trees {e.g. ash) is corre- 

 ! lated with the character of their wood. The sap wood 

 of deciduous trees commonly fills up with water during 

 j the early autumn, and grounds are -shown for observ- 

 ! ing caution in fitting conclusions reached in other 

 climates to the circumstances that obtain in the British 

 Isles. This matter is of some importance in its bear- 

 ing on the conditions that affect the seasoning of 

 timber. — Capt. M. Greenwood : The efficiency of muscu- 

 lar work. It is shown that the relation between total 

 heat production, body mass, and external work can 

 be expressed with sufficient accuracy for interpolation 

 by a function of the first degree, the constants of which 

 I have been determined from the data by the method 

 ! of multiple regression. The method is illustrated upon 

 ! the data of Macdonald and those of Amar. When 

 ! body mass is constant, the relation is H = aW + b, H 

 being total heat production, W the thermal equivalent 

 of the work, a a constant, and b a variable parameter 

 dependent upon the speed of work performance. The 

 parameters are calculated for the data of Benedict and 

 j Cathcart. It is pointed out that the relation neces- 

 sarily involves an increase of efficiency with amount of 

 work when efficiency is defined as W/H or as 

 , W/{H-h), h being the "basal" heat production, and 

 that this increase may be without biological signifi- 

 cance. Reasons are given for doubting whether the 

 I general relation between heat production and muscular 

 I efficiency can be safely inferred from existing series of 

 observations, and economy of thermogenesis is dis- 

 cussed. 



Linnean Society, February 7. — Sir David Prain, presi- 

 dent, in the chair. — Dr. B. Daydon Jackson : (i) The 

 " Panphyton siculum " of Francesco Cupani (1657- 

 17 10). A few copies, none of which were complete, 

 were issued in 1713 by Cupani's patron, the Prince 

 Delia Cattolica, the copy in the library of the Jesuit 

 Fathers at Palermo being the nearest complete, and 

 therefore cited by Gussone in his " Prodromus " and 

 "Synopsis"; it consists of three volumes with about 

 700 plates, without text; the copy in the Linnean 

 Society's library has only 196 plates, two of which are 

 in duplicate. (2) " L'Histoire et pourtrait des plantes," 

 Lyon, 1561. The volume belonged to Linne, and a 

 pencil note on the title-page by Smith refers to an 

 entry in Haller's " Bibliotheca botanica," vol. i., p. 318, 

 which proves to be copied from Adanson's "Families 

 ' des plantes," vol. i., p. 6, where the book is described 

 I from jussieu's library, but Jussieu's copy is given as 

 j published at Rouen in 1555, and attributed to Du Gort; 

 the brothers Jean and Robert Du Gort were printers at 

 ! Rouen at that time, and probably drew up the volume 

 from the Lyons issue of Fuchs's " Historia stirpium " 

 j of 1551, for nineteen of the cuts ^re identical in both 

 i books, with eight not yet»traced. — H. B. Guppy : Plant- 

 I distribution from the point of view of an idealist. The 

 paper began with an appeal for the mutual co-operation 

 of the supporters of the original Darwinian theory of 

 I evolution and of the later hypothesis of mutation ad- 

 j vanced by De Vries. If the view is correct that in the 

 I history of the .Angiosperms we have two main eras — 

 the era of the rise of the great families and the era of 

 i their later differentiation — the mutationist would find 

 I his most fitting field of work in the older era and the 

 orthodox Darwinian in the later one. It is held that 

 the distinction between the two schools is in degree 

 rather than in kind, and that the age that witnessed 

 the rise of the great families and the age that wit- 

 nessed their later differentiation are things apart. Dis- 

 tribution is orimarilv an affair of the larger groups ; 

 and the problems that centre around the rise of the 

 great families raise issues that cannot be stated in 



