33^ 



NATURE 



[May 19, 1 9 10 



ktlas of Japanese Vegetation. With explanatory 

 text. Edited by Prof. M. Miyoshi, Set xiii., 

 plates 86-92, pp. 6 : Coast Vegetation of Middle 

 Japan. Set xiv., plates 93-101, pp. 7: Mountain 

 Vegetation of Northern Japan. (Tokyo : L. P. 

 Maruya and Co., Ltd. ; London : W. Wesley and 

 Son. 1909.) 

 The series of botanical plates illustrating- Japanese 

 vegetation, of which the two sets under notice are 

 late numbers, are phototype reproductions illustrating 

 plant-landscapes and a few cultivated plants, arranged 

 for the most part topographically. The thirteenth set 

 contains photographs of a temperate region, in which 

 Pinus Thunbergii is a typical tree along the coast. 

 It is shown with a foreground in one case of Rosa 

 riigosa, and in another of Calystegia soldanella. 

 Another photograph represents a broad expanse of 

 the Calystegia, and two plates show a curious 

 segregation of male and female plants of Carex 

 macrocephala. The nine plates forming the fourteenth 

 set are taken from three different mountains. Two 

 photographs taken on Mount Azuma depict Rhodo- 

 dendron Albrechtii and a natural double-flowered 

 variety of Rhododendron brachycarpiim. The scenes 

 from "Mount lide include a fine spread of Phyllodoce 

 aleutica interspersed with Geum dryadoides, and an 

 association of Geranium davuricum with Adenophora 

 polymorpha. Mount Iwate is the station which pro- 

 vides an unexpected combination of Rhododendron 

 kamtschaticum and Pinguicula vulgaris. The illus- 

 trations, measuring about nine inches by six inches, 

 are remarkably sharp and well defined, and are highly 

 creditable to Prof. M. Miyoshi and Mr. G. Nakhara, 

 who are responsible for the original negatives. 



Actualitds scientifiques. By Max de Nansouty. Pp. 



380. (Paris : Schleicher Fr^res, 1909.) Price 3.50 



francs. 

 This interesting "annual" of M. Max de Nansouty, 

 the sixth to appear, will be welcomed by the general 

 reader anxious to acquaint himself, in as pleasant a 

 manner as possible, with the more popular of the 

 recent advances" in science. It is natural in this issue 

 to see great prominence given to the problems in 

 connection with aviation and to electricity in its 

 applications, but readers will find that most branches 

 of science have been drawn upon to produce an inter- 

 esting miscellany. The volume may be recommended 

 specially to students of science anxious to keep up 

 their French without neglecting their own special work 

 unduly. 



Mathematical Tables : with Full Tables of Mathe- 

 matical and General Constants. By R. W. M. 

 Gibbs and G. E. Richards. Pp. 17. (London : 

 Christophers, n.d.) Price 8d. net. 

 These conveniently arranged tables provide all that 

 pupils in ordinary secondary schools and technical 

 classes require in their mathematical and science 

 lessons. They include logarithms and antilogariihms, 

 natural and logarithmic sines and cosines, tangents 

 and cotangents, and tables of formulae and data. 



Weighing and Measuring. A Short Course of Prac- 

 tical Exercises in Elementary Mathematics and 

 Physics. By W. J. Dobbs. Pp. ix+176. (London: 

 Methuen and Co., 1910.) Price 25. 



Though there is little that is new either in the method 

 or contents of this book, teachers will find here a 

 clear, wiell-arranged set of practical lessons on the 

 measuremieht of length, area, volume, mass, and 

 density. An abundant provision of questions — original 

 and otherwise — has been made, especially for candi- 

 dates in the Army Qualifying Examination. 



NO. 2116, VOL. 83] 



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 is taken of anonymous communications.] 



A Sponge with a Siliceous and Calcareous Skeleton. 



In Willey's " Zoological Results," part iv., 1900, J. J. 

 Lister described certain small columnar coral-like organisms 

 from 35-100 fathoms off Lifu and Funafuti as calcareous 

 sponges. He named them Astrosclera willeyana, and, on 

 account of their isolated position, placed them in a new 

 family — Astrosclerida*. The skeleton was formed of minute 

 calcareous spherules, separate above, but welded below 

 into solid walls and blocks, the spherules being formed each 

 in a single cell. 



Recently Dr. C. W. Andrews obtained from 46 fathoms 

 off Christmas Island four more specimens of this sponge. 

 A decalcified section showed that Astrosclera was prob- 

 ably a siliceous Ectyonine sponge, for its canal walls 

 were bristling with spiny nail-shaped siliceous spicules 

 (Fig. 2). I concluded that this siliceous sponge had formed 

 a supplementary calcareous skeleton from foreign particles 

 which had been picked up from outside, so extremely 

 improbable did it seem that a sponge could secrete both 

 lime and silex. Later preparations, however, have showt> 



Fig. I. — A specimen oi Astrosclera willeyana, Lister. Natural size. 

 Fig. 2. — Section showing laminae and masses of calcareous spherules, and 

 nail-shaped siliceous spicules. X 50. 

 Fig. 3.— Nucleated cells containing calcareous spherules. x6oo. 



me that Lister was right, and that each spherule (appar- 

 ently of conchite) is formed in a single cell (Fig. 3). 



Fig. I is that of a living specimen and not of a dead 

 stock, and yet I can find no trace of anything else than 

 sponge tissue and spherule cells. Further, the superficial 

 stellate grooves which are excavated in the calcareous mass 

 are formed by the terminal exhalant canals of a sponge. 



I continue to regard Astrosclera as a siliceous sponge, 

 though I have just become aware that an eminent German 

 zoologist has a very different opinion concerning its 

 nature. Assuming that my theory is correct, .Astrosclera 

 may possibly owe its unique character to an ancestral 

 habit of picking up foreign particles — in this case — of 

 calcareous detritus, for the sponge has only been found on 

 coral reefs. Some of the lime would dissolve and become 

 re-crystallised in the connective tissue cells. When once 

 this character had been acquired, the clumsy method of 

 the sponge choking itself up with debris would be re- 

 placed by the more " scientific " process of elaborating lime 

 direct from the sea water. I hope soon to set forth in 

 detail the pros and cons, of this theory. 



R. KiRKPAtRICK. 



British Museum (Natural History), South Kensington. 



