THE PROGRESS OF SCIENCE 



415 



as enzymes, that effect assimilation 

 and disassimilation. Quite similar 

 changes can be produced outside the 

 body {in vitro) by the employment of 

 methods of a purely physical and 

 chemical nature. It is true that \\e 

 are not yet familiar with all the inter- 

 mediate stages of transformation of 

 the materials which are taken in by a 

 living body into the materials which 

 are given out from it. But since the 

 initial processes and the final results 

 are the same as they would be on 

 the assumption that the changes are 

 brought about in conformity with the 

 known laws of chemistry and physics, 

 we may fairly conclude that all changes 

 in living substance are brought about 

 by ordinary chemical and physical 

 forces. 



' ' Should it be contended that growth 

 and reproduction are properties pos- 

 sessed only by living bodies and con- 

 stitute a test by which we may differ- 

 entiate between life and non-life, be- 

 tween the animate and inanimate crea- 

 tion, it must be replied that no conten- 

 tion can be more fallacious. Inorganic 

 crystals grow and multiply and repro- 

 duce their like, given a supply of the 

 requisite pabulum. In most cases for 

 each kind of crystal there is, as with 

 living organisms, a limit of growth 

 which is not exceeded, and further in- 

 crease of the crystalline matter results 

 not in further increase in size but in 

 multiplication of similar crystals. 

 Leduc has shown that the growth and 

 division of artificial colloids of an in- 

 organic nature, when placed in an ap- 

 propriate medium, present singular 

 resemblances to the phenomena of the 

 growth and division of living organ- 

 isms. Even so complex a process as | 

 the division of a cell-nucleus by karyo- : 

 kinesis as a preliminary to the multi- 

 plication of the cell by division — a 

 phenomenon which would prima facie 

 have seemed and has been commonly 

 regarded as a distinctive manifestation 

 of the life of the cell — can be imitated 

 with solutions of a simple inorganic 

 salt, such as chloride of sodium, con- 



taining a suspension of carbon par- 

 ticles; which arrange and rearrange 

 themselves under the influence of the 

 movements of the electrolytes in a 

 manner indistinguishable from that 

 adopted by the particles of chromatin 

 in a dividing nucleus. And in the 

 process of sexual reproduction, the re- 

 searches of J. Loeb and others upon 

 the ova of the sea-urchin have proved 

 that we can no longer consider such an 

 apparently vital phenomenon as the 

 fertilization of the egg as being the 

 result of living material brought to it 

 by the spermatozoon, since it is pos- 

 sible to start the process of division of 

 the ovum and the resulting formation 

 of cells, and ultimately of all the tis- 

 sues and organs — in short, to bring 

 about the development of the whole 

 body — if a simple chemical reagent is 

 substituted for the male element in 

 the process of fertilization. Indeed, 

 even a mechanical or electrical stim- 

 ulus may suffice to start development. 

 Kurz unci gut, as the Germans say, 

 vitalism as a working hypothesis has 

 not only had its foundations under- 

 mined, but most of the superstructure 

 has toppled over, and if any difficulties 

 of explanation still persist, we are 

 justified in assuming that the cause is 

 to be found in our imperfect knowl- 

 edge of the constitution and working 

 of living material. At the best vital- 

 ism explains nothing, and the term 

 'vital force' is an expression of ignor- 

 ance which can bring us no further 

 along the path of knowledge. Nor is 

 the problem in any way advanced by 

 substituting for the term 'vitalism' 

 'neo-vitalism,' and for 'vital force' 

 'biotic energy.' 'New presbyter is but 

 old priest writ large. ' 



SCIENTIFIC ITEMS 



We record with regret the deaths of 

 Dr. W J McGee, known for his con- 

 tributions to geology, anthropology and 

 the conservation of natural resources; 

 of Dr. T. B. McClintic, of the United 

 States Public Health Service, who died 



