NATURE 



217 



THURSDAY, JULY 5, 1900. 



PROTOPLASM. 



Allgenieine Biologie. By Prof. Dr. Max Kassowitz. Vols. 



i. and ii.. Pp. xv + 411, and x + 391, (Vienna: 



Moritz Pedes, 1899). 

 A B.A.D hypothesis is better than none at all, is a 

 ■^"^ saying of which many have taken advantage ; but 

 able minds have agreed with the substance of the remark, 

 and few can dissent from it in connection with that ever- 

 lasting puzzle — Protoplasm. It is in vain to inveigh 

 against the uselessness of speculations as to the structure 

 or constitution, nature — what you will — regarding the 

 physical basis of life, or regarding attempts to picture, 

 however roughly, the movements, rearrangements and 

 evolutions in that veritable witches' dance, the quadrilles 

 of the molecules in which life consists. The inquiring 

 mind is so constituted that it cannot resist the temptation 

 to fashion some rough hypothesis as a tool wherewith to 

 make one more attempt to pick the lock which hides the 

 secret, and the criticism of the serious as to the futility of 

 his eftbrts is no more powerful than the epigram of the 

 debater to prevent him returning to the ruins of previous 

 speculations, with renewed efforts to rebuild his frail 

 image of something approaching, as nearly as may be, 

 the inconceivably complex, and exposing it once more 

 to the blows of the critic. 



To those who are hopeless, let the more hopeful point 

 out the difference in our present ideas of the nature of 

 protoplasm from those of twenty years ago, and say 

 whether no advances have been made. 



In this extraordinarily well-written work, it is satisfac- 

 tory to see that the word Biology is used in the sense of 

 "the science of life," and not in the restricted and often 

 unintelligible way so common in Continental works. Still 

 more satisfactory is it to find here a carefully thought out 

 plan of re-examination of the fundamental phenomena of 

 life, and of " the physical basis of life," on which is erected 

 a hypothesis with bold outlines and stately proportions, 

 yet carefully and minutely fitted details, in conformity 

 with the rapidly advancing knowledge of the last two 

 decades. 



The subject of " AUgemeine Biologie," as treated by 

 the Viennese professor, resolves itself under the following 

 headings : — 



I. "Aufbau und Zerfall des Protoplasmas," forming 

 the theme of the first volume, which is further sub- 

 divided into: (i) "Das Problem des Lebens und die 

 Versuche zur Losung desselben " ; (2) "Aufbau des 

 Protoplasmas " ; and (3) " Zerfall des Protoplasmas." 



II. The second volume is entitled " Vererbung und 

 Entwicklung." 



The third and fourth volumes are not yet to hand, but 

 we are informed that they will deal with " Stoff- und 

 Kraftwechsel der Thiere " and with " Nerven und Seele " 

 respectively. That they will be eagerly looked for by all 

 who have read the two at present under review is a safe 

 prophecy. 



Kassowitz takes his stand on the conviction — the 

 reasons for which are given at great length in the first 

 NO. 160I, VOL. 62 1 



half of the first volume — that previous hypotheses as to 

 the nature of protoplasm, based on assumptions that any 

 structure visible after treatment can be translated in 

 terms of its structure during life, break down on examin- 

 ation equally with those which would regard protoplasm 

 as a mere emulsion ; and that all attempts to explain 

 what is going on in living protoplasm, which have for 

 their basis the assumption that oxidations, reductions, 

 and metabolic changes generally are carried out in the 

 fluids bathing any such machinery of the protoplasm 

 also fail to withstand criticism. The thermodynamic 

 theory of life fails because the engine itself burns, and 

 the value of a substance as food has no relation to its 

 combustible value. It might have been added that 

 Pfeffer had already shown this in his treatise " Zur 

 Energetik der Pflanze." The osmotic theory of the 

 botanists breaks down, because it attributes to the cell- 

 sap an importance which a mere solution under such 

 conditions does not possess ; the fermentation theory 

 fails to explain more than a few bye-phenomena of life, 

 and has no help for us in questions concerning synthesis ; 

 the electro-dynamic theory breaks down because electric 

 phenomena are least obvious just where we should most 

 expect them. The molecular-physical theory assumes 

 vibrations and the shaking asunder of molecules which 

 are so stable that it is impossible to believe that they 

 could be shattered and others escape under the con- 

 ditions imposed ; while the vitalistic theory is a mere 

 confession that what is to be explained needs explanation. 



Underneath or behind all the assumptions of micelUe, 

 gemmules, biophores, determinants or other formed struc- 

 tural units, as well as all material networks, rods, 

 spherules, fibrils, pellicles and foams, Kassowitz detects 

 the question — Of what are these physiological units 

 and structures composed ? And he regards the funda- 

 mental fallacies underlying all previous hypotheses 

 regarding the constitution and working of living proto- 

 plasm as chiefly two : — viz. the assumption that proto- 

 plasm is composed of proteids built up into some sort of 

 more or less stable machinery, and that the chemical 

 and other changes usually comprised in the term 

 metabolism are carried on outside or merely in contact 

 with this machinery — e.g. in a meshwork, or on the 

 surface of the physiological units. 



He therefore proposes to examine in detail, and step 

 by step, what comes of deductions made from the hypo- 

 thesis that protoplasm consists of molecules, in the 

 chemical sense, but of extreme complexity, large volume, 

 and very labile, hnked one to another in series, and each 

 requiring for its construction, not only proteids, but also 

 fats, carbohydrates and the mineral salts known to be 

 indispensable for life. And that every vital act consists 

 in destructions and reconstructions of these molecules. 



To obtain a coarse picture of this invisible structure 

 we may suppose extremely tenuous fibrils of india-rubber 

 joined up into a complex network and bathed in a fluid 

 which contains the necessary ingredients for putting in 

 new pieces wherever, by stretching the net too far, we 

 break the elastic strands ; such breakages will occur 

 especially between the nodes, and immediately the gaps 

 are bridged over again by new fibrils, or networks of 

 such, further extension, breakage and restitution are 

 possible. 



