SCIENCE- GOSSIP. 



285 



CONDUCTED BY WILFRED MARK WEBB, F.L.S. 



Monograph of British Land Shells. — The 

 notice of the fifth part of J. W. Taylor's Monograph, 

 which has already appeared in Science-Gossip {ante, 

 p. 242), deals more with the treatment of the ana- 

 tomical points than with that accorded to questions of 

 physiology. Admirably maintained as is the general 

 excellence of the work, it is to be regretted that the 

 physiology of the present instalment falls so far short 

 of the anatomy. On more than one occasion Mr. 

 Taylor has made statements which cause one to 

 regret more than ever that he has not seen fit as yet 

 to give references to his authorities beyond two short 

 lists in the earlier parts of the work. If, for instance, 

 one would refer to the original of fig. 515, in the 

 hope of finding further details about the development 

 of the radula, one has to go elsewhere to discover 

 where RSssler's paper is to be found, and so on in 

 many other cases. This apparent abhorrence of any 

 reference to other literature can hardly arise from 

 considerations of economy of space when such 

 elaborate details are given as to the place of origin 

 and the captor of typical specimens figured. Perhaps 

 a bibliography will appear in time. There does not 

 seem, however, to be any means of referring the 

 different parts of the text to such a list, beyond a 

 certain number of names, which in any case will 

 make reference very difficult. On p. 280 we learn 

 that "the ferment is a rather thin, dark yellowish 

 fluid, decolorised and dissolved by nitric acid, and is 

 probably a derivative of haematoidin." It would 

 surely have been as well to give some authority, 

 unless it is an observation by Mr. Taylor himself, for 

 the highly original proposition that a digestive ferment 

 is derived from a pigment related to haemoglobin, or 

 from a vertebrate bile-pigment. The discovery by 

 W. Biedermann and S. Moritz (Pfliiger's Archiv, 

 vol. lxxiii. [1898], pp. 219-287 : abstract in Journ. 

 Chem. Soc, March 1899, p. 166) of a ferment 

 apparently secreted by the ' ' liver " in Helix pomatia, 

 which is capable of dissolving cellulose, is not men- 

 tioned. The formula given for glycogen on p. 280 

 is, we presume, only a printer's error, and on the 

 next page there seems to be some confusion as to the 

 conditions which influence the presence of this sub- 

 stance in the liver. It is said to disappear entirely 

 after one to three days' fasting, and yet an estimable 

 quantity is present during hibernation. The work of 

 Barfurth on the metabolism of inorganic salts by the 

 liver in H. po7natia seems to share an unworthy 

 oblivion with similar work by Dastre and others. 

 The derivation given on p. 295 for haemoglobin 

 may be ultimately correct, but it hardly seems likely 

 that Hoppe-Seyler was thinking of spheres when he 

 gave the name. Further on (pp. 282-3) we read, 

 "This absorption of the nutritive products of digestion 

 from the alimentary canal is not accomplished by 

 special organs, as in vertebrates, but is effected by 

 endosmosis through the intestinal walls into the 

 blood contained within a plexus of blood vessels dis- 



tributed over the whole surface of the alimentary 

 canal." We can only ask Mr. Taylor for further 

 information as to what the special absorptive organs 

 are in vertebrates which are absent in the mollusca, 

 and what the evidence may be that in the snail absorp- 

 tion takes place by "endosmosis." The account of 

 the chemistry of the blood seems inadequate ; and 

 it would be almost worth while in a work of this size 

 to quote some analyses in detail ; the work of A. B. 

 Griffiths, at any rate (Proc. Roy. Soc. Edinb. 

 vol. xviii. pp. 292-3, and in Physiol, of Invert, pp. 

 141 and 145) is easily available. The words on 

 p. 296 to the effect that "the Amoebocytes seem 

 from their origin to be connective tissue cells 

 especially adapted to live in an albuminous medium," 

 imply that connective tissue cells, as a rule, live in 

 a non-albuminous medium, which would be a diffi- 

 cult proposition to establish ; and in connection with 

 the same subject attention may be called to the fact 

 that all the wandering cells of the blood are not by any 

 means necessarily phagocytic. A full and interest- 

 ing account is given of the relation of snails to 

 plants and of the influence of temperature and some 

 other conditions on the rate of the heart-beat and on 

 the rate of respiration, but nothing seems to be said 

 about what is known as to the action of other factors 

 (drugs, &c. ) on the snail's heart, nor about the 

 quantitative chemistry of the respiratory exchange in 

 relation to temperature (see H. M. Vernon, Journ. of 

 Physiol, xxi. [1897] p. 454). The opinion of 

 Merejkowski (1881) that tetronerythrin is respiratory 

 in function, quoted (without authority) on p. 307, 

 has been seriously challenged by Halliburton (Journ. 

 of Physiol, vi. [1885] p. 327), and according to the 

 usage of the inventor of the names and others, myohae- 

 matin is one of the histohaematins. It may be said, 

 and very likely quite correctly, that in a work of the 

 present kind an elaborate and detailed account of 

 the physiology of the mollusca, or of the little we 

 know of it, would be out of place. If nothing had 

 been said about, e.g., the natures of ferments or 

 leucocytes, no exception could have been taken to 

 what would have been a very reasonable omission. 

 Yet since Mr. Taylor has gone into such matters at 

 all, it is a pity that he has not given us something 

 less superficial, and, one would venture to say, less 

 inaccurate, than some of the sentences to which we 

 have called attention. We would finally like to 

 raise a protest against the use of the Fahrenheit 

 scale of temperature, which is as objectionable as the 

 previous use of grains in the matter of weight. The 

 value of the excellent illustrations is also in some 

 cases considerably diminished by the practice of not 

 giving even the approximate magnification of the 

 enlarged figures ; thus figures 564 and 587 are both 

 " highly magnified," but, if one were to suppose that 

 the two objects were anything like equally enlarged, 

 one would get a strange idea of the size of either the 

 gut or the leucocytes ; and with which of these are we 

 to compare fig. 606, also marked "highly magni- 

 fied"? Fig. 572 would appear to be natural size, 

 but it must have been a Helix virgata of record size 



to yield such a preparation Arthur E. Boycott. 



Production of Sound by Mollusca. — Our in- 

 digenous forms are not usually credited with the power 

 of emitting any sounds which might reasonably be 

 called audible. I have, however, frequently noticed 

 that the sound, something like " pblopb," caused by 

 Limnaea stagnalis opening their respiratory orifices 

 at the surface of the water, may be heard some 

 distance. — Arthur E. Boycott, 31 Walton Crescent, 

 Oxford, 



