THE MECHANISTIC CONCEPTION OF LIFE 17 



7. The Harmonious Chaeactee of the Organisms 



It is not possible to prove in a short address that all life phenomena 

 will yield to a physico-chemical analysis. We have selected only the 

 phenomena of fertilization and heredity, since these phenomena are 

 specific for living organisms and without analogues in inanimate na- 

 ture; and if we can convince ourselves that these processes can be ex- 

 plained physico-chemically we may safely expect the same of such 

 processes for which there exist a priori analogies in inanimate nature, 

 as, e. g., for absorption and secretion. 



"We must, however, settle a question which offers itself not only to 

 the layman but also to every biologist, namely, how we shall conceive 

 that wonderful " adaptation of each part to the whole " by which an 

 organism becomes possible. In the answer of this question the meta- 

 physician finds an opportunity to put above the purely chemical and 

 physical processes something specific which is characteristic of life only : 

 the " Zielstrebigkeit," the " harmony " of the phenomena, or the 

 " dominants " of Eeinke and similar things. 



With all due personal respect for the authors of such terms I am 

 of the opinion that we are dealing here, as in all cases of metaphysics, 

 with a play on words. That a part is so constructed that it serves the 

 " whole " is only an unclear expression for the fact that a species is only 

 able to live — or to use Roux's expression — is only durable, if it is pro- 

 vided with the automatic mechanism for self-preservation and repro- 

 duction. If, for instance, warm-blooded animals should originate with- 

 out a circulation they could not remain alive, and this is the reason 

 why we never find such forms. The phenomena of " adaptation " cause 

 only apparent difficulties since we rarely or never become aware of the 

 numerous faultily constructed organisms which appear in nature. I 

 will illustrate by a concrete example that the number of species which 

 we observe is only an infinitely small fraction of those which can origi- 

 nate and possibly not rarely do originate, but which we never see since 

 their organization does not allow them to exist long. Moenkhaus found 

 ten years ago that it is possible to fertilize the egg of each marine bony 

 fish with the sperm of practically any other marine bony fish. His 

 embryos apparently lived only a very short time. This year I suc- 

 ceeded in keeping such hybrid embryos between distantly related bony 

 fish alive for over a month. It is, therefore, clear that it is possible to 

 cross practically any marine teleost with any other. 



The number of teleosts at present in existence is about 10,000. If 

 we accomplish all possible hybridization 100,000,000 different crosses 

 will result. Of these teleosts only a very small proportion, namely about 

 one one-hundredth of one per cent., can live. It turned out in my ex- 

 periments that the heterogeneous hybrids between bony fishes formed 



VOL. LXXX. — 2. 



