414 



NATURE 



[September i, 1892 



mass of information on its more important topics. It is 

 only natural that a work which is essentially a compila- 

 tion, should be of a somewhat patchwork character ; but 

 it is to be regretted that in some of the sections the 

 different parasjraphs do not offer more coherent reading. 

 It would further have been an advantage to the general 

 public, whose education in these matters is so essential 

 an element in the further progress of public health, if so 

 many technical terms had not been used without ex- 

 planation. Occasional looseness of expression is to be 

 noticed. As when we read of "Bacterium termo, the 

 microbe of impure water," or, "the Zeiss system m\gni- 

 fies three to four thousand times." But to those for 

 whom the book is specially written, those interested or 

 officially concerned in the promotion of health, it will 

 prove a valuable work of reference. 



THE PHYSIOLOGY OF THE INVERTEBRA TA. 



The Physiology of the Invertebrata. By A. B. Griffiths, 

 Ph.D., F.R.S. (Edin.), F.C.S. (London : L. Reeve and 

 Co., 1892.) 



STUDENTS of biology, and especially of physiology, 

 have long wanted a book treating of the physio- 

 logical problems of the invertebrate animals. It is true 

 that what is sometimes called human physiology is in 

 great measure the physiology of the lower animals. 

 Physiologists, however, generally select for experiment 

 animals which are as much as possible like themselves ; 

 it is comparatively seldom that they invade the inverte- 

 brate branches of animal life. There are vast fields there 

 for exploration which are almost untouched from the 

 physiological standpoint, and one can hardly doubt that 

 great treasures in the way of fact and reasoning could be 

 unearthed, which would throw light on the functions not 

 only of these lower creatures themselves, but on the life 

 problems of the higher animals also. The present book 

 by Dr. Griffiths will therefore be welcomed as a first 

 attempt to fill this gap. He is well known as one of the 

 few who have cari'ied the method of physiology down to 

 the invertebrates, and his researches have been marked 

 by great industry and patience. 



In treating of invertebrate physiology, it is obvious that 

 there are two courses open to a descriptive writer : one is 

 to take the various sub-kingdoms as the main headings 

 and to treat of the different functions of each before pro - 

 ceeding to the next ; the other method is to head the 

 chapters with the functions — circulation, respiration, and 

 the like — and to describe each of these in the various 

 branches of the invertebrata. No doubt there is much to 

 be said for each course. The latter, which is the one 

 adopted in the present volume, appears, however, to have 

 these disadvantages, that it involves a good deal of repeti- 

 tion, and that each chapter is split up into a number of 

 small paragraphs, and there is thus but little continuous 

 narrative. This is increased by the habit the author has 

 of making extensive quotations, so that there is little 

 uniformity of style ; half a page will be given in the 

 flowing style of Huxley, and the next half in the less 

 fluent English of other writers. It appears to us it would 

 have b8en better if Dr. Griffiths had given the results of 

 other investigators in his own language. This, however, 

 NO. TI92, VOL. 46] 



is a minor point. Passing to more important matters, we 

 may proceed to enquire if the book really meets the want 

 which has been stated to exist ; and the answer to such 

 an enquiry must depend on whether the good in it out- 

 weighs the bad, or the reverse. The features in the book 

 which appear to be excellent, are, first, the evidence that a 

 vast amount of pains has been expended in its compila- 

 tion ; and on those subjects to which the author has 

 devoted research-work — the excretions, the blood gases 

 and salts, and digestion — he is distinctly good, and men 

 of science will be glad to have all Dr. Griffiths' experi- 

 mental work in a handy form, instead of having to hunt 

 it out from journals. Then the whole is exceedingly 

 interesting, and will no doubt stimulate others to prose- 

 cute new work on the subject. 



There is, however, much that must come in for adverse 

 criticism, and the first point to which attention may be 

 called is not so much the fault as the misfortune of the 

 author in having to deal with a portion of biological 

 science which is in an embryonic condition. Where little 

 is known little can be said, and some of the chapters are 

 little more than anatomy, with physiological excerpts from 

 anatomical works. Again, on certain subjects such as 

 muscular contraction and blood coagulation, the author 

 is evidently not acquainted with the literature of his 

 subject, and in other cases again there is internal evidence 

 to show that Dr. Griffiths has not consulted original 

 memoirs, but abstracts of them that have appeared else- 

 where. 



The main objection, however, that physiologists will 

 feel about the work, is the conclusion to which they can 

 hardly help coming, that Dr. Griffiths has not the advan- 

 tage of being a physiologist ; there is no wide grasp of 

 the facts and hypotheses with which he has to deal, and 

 the hand of the amateur is continually to be seen. Take 

 as an instance the following sentences : '' Urea is a pro- 

 duct of more or less complete oxidation of organic sub- 

 stances, and is formed in muscular tissues by the 

 disintegration of the anatomical elements. Uric acid on 

 the other hand is the result of an incomplete oxidation, 

 and is produced for the most part in the blood, or its 

 equivalent when such fluid is surcharged with peptones 

 which the tissues are unable to assimilate." (The italics 

 are our own.) Again, in the chapter on the physiology 

 of the sense organs, the difference between the tactile 

 sense and general sensibility has not been apparently 

 grasped ; and even on subjects which the author has him- 

 self investigated, very often elementary facts , have 

 escaped him. Thus it appears that uric acid is the most 

 constant of the nitrogenous metabolites in the inverte- 

 brata, but we are not in the majority of instances told 

 how this insoluble substance is held in solution in an 

 aqueous liquid. We also read that after starch has been 

 digested with the secretion of the hepato-pancreas, it 

 gives a precipitate of cuprous oxide with Trommer's test, 

 and this is regarded as sufficient evidence of the forma- 

 tion of glucose. No reference is made to the fact that 

 anylolytic ferments in the vertebrata produce maltose and 

 not glucose from starch. Again, one would judge from 

 Dr. Griffiths' words, that he regards the formation of 

 leucine and tyrosine as the chief functions of a proteolytic 

 ferment, or from the omission of hasmocyanin from the 

 chapter on respiration that it was not a respiratory pig- 



