Febbuaey 25, 1910] 



SCIENCE 



305 



The logical weakness of this argument is 

 at once supported by the circumstance that 

 the protoplasm which differentiates the ma- 

 chinery is a liquid, and as all stresses and 

 strains in a fluid are instantly equalized, 

 liquid machines are physical impossibilities. 

 The protoplasm of the egg is, therefore, no 

 machine, and is forever beyond the reach of 

 mechanical investigations. Physiology, anat- 

 omy, chemistry and physics are all powerless 

 to grapple with this problem. The essence of 

 a living thing is that it is vital, and this at- 

 tribute, if accessible to the human intellect 

 at all, can be understood only by the aid of 

 " reine Erkennungslehre." 



Whether vitalism will triumph ultimately, 

 is one of the many things that most biologists 

 do not know, although von Uexklill considers 

 victory inevitable. Lack of philosophical in- 

 sight is held responsible for the bankrupt con- 

 dition of our science, but however this may be, 

 to restore confidence in biological currency by 

 means of an inflation of vitalistic values 

 seems a doubtful undertaking even if liquid 

 machines are impossible. But is protoplasm 

 a liquid? 



The naked amoebae are the most fluid of all 

 animals, nevertheless their outer layers are 

 visibly different from the interior, and there 

 is every reason to believe that the ectosarc 

 subserves many of the functions performed by 

 the firmer boundaries of other cells. Among 

 these functions is that of being a barrier 

 which prevents the animal from becoming in- 

 finitely diluted in the medium in which it 

 lives. Furthermore, the ectosarc, like the cell 

 membrane, allows certain substances to pass 

 in and out, and in this way insures differences 

 in chemical composition between the amoeba 

 and its surroundings, while at other times it 

 is the gate through which the equalization of 

 differences is brought about. As long as 

 protoplasm does not exist abstractly, but al- 

 ways occurs in nature behind a barrier that 

 makes possible interrelations with the environ- 

 ment, and prevents fusion and identity with 

 it, arguments based on a liquid as it isn't, can 

 have no bearing on the case of vitalism vs. 

 mechanism. 



We will suppose, however, that the optical 

 differences between the ectosarc and the endo- 

 sarc are illusory; that the outer layers of the 

 most fluid of all amoebse are not physiolog- 

 ically the equivalents of cell-membranes; and 

 flnally that we are in reality dealing with 

 liquids entirely uniform. We will endow 

 these microscopic Frankensteins with life. 

 Are they machines? 



Abstractly — no; concretely — yes, for our 

 imaginary creatures exist in an environment, 

 and interaction between the two is the one 

 condition under which life is possible. As 

 long as such interaction occurs, as long as 

 metabolism takes place, we have differences of 

 potential, stresses and strains; as long as any- 

 thing happens, and life is a happening, we 

 have a mechanism, a machine, but the ma- 

 chinery is neither the amceba nor the environ- 

 ment, but the two together. Von Uexkiill's 

 own contention that an organism devoid of 

 environment is an absurdity, harmonizes so 

 completely with this criticism, that it is diffi- 

 cult to see how the road which he has traveled 

 could ever have led him into the vitalistic 

 man-trap. 



To make a good book, however, does not re- 

 quire infallibility. Thought, honesty and 

 clearness are the necessary ingredients, and a 

 writer who commands these fertilizes the 

 minds of his readers, and where wrong, fur- 

 nishes the materials for the correction of his 

 own mistakes. Even though von Uexkiill 

 seems to have failed in some of his under- 

 takings, he is nevertheless an author thor- 

 oughly worthy to be read. 



Otto C. Glaser 



University of Michigan 



Handbuch der Klimatologie. Band II., Kli- 

 matographie. I. Teil, Klima der Tropen- 

 zone. Dritte, wesentlich umgearbeitete und 

 vermehrte Auflage. Von Dr. Julius Hann. 

 8vo, pp. x-4-426, figs. Y. Stuttgart, J. 

 Engelhorn. 1910. Preis 14 M. 

 The first part of the second volume of the 

 third edition of Hann's monumental work — 

 revised, enlarged, up to date — ^the unique store- 

 house of olimatological fact and description; 

 the indispensable reference book for all who 



