lO 



NATURE 



[September 5, 1912 



transformations undergone by the nucleus are without 

 importance ; but it is none the less true that even in 

 an amorphous condition the material which in the 

 ordinary cell takes the form of a " nucleus " may, in 

 simpler organisms which have not in the process of 

 evolution become complete cells, fulfil functions in 

 many respects similar to those fulfilled by the nucleus 

 of the more differentiated organism. 



A similar anticipation regarding the probability of 

 eventual synthetic production may be made for the 

 proteins of the cell-substance. Considerable progress 

 in this direction has indeed already been made by 

 Emil Fischer, who has for many years been engaged 

 in the task of building up the nitrogenous combina- 

 tions which enter into the formation of the complex 

 molecule of protein. It is satisfactory to know that 

 the significance of the work both of Fischer and of 

 Kossel in this field of biological chemistry has been 

 recognised by the award to each of these distinguished 

 chemists of a Nobel prize. 



Ihe Chemical Constitution of Living Substa)tce. 

 The elements composing living substance are few 

 in number. Those which are constantly present are 

 carbon, hydrogen, oxygen, and nitrogen. With these, 

 both in nuclear matter and also, but to a less degree, 

 in the more diffuse living material which we know as 

 protoplasm, phosphorus is always associated. " Ohne 

 Phosphor kein Gedank " is an accepted aphorism ; 

 "Ohne Phosphor kein Leben " is equally true. More- 

 over, a large proportion, rarely less than 70 per cent., 

 of water appears essential for any manifestation of 

 life, although not in all cases necessary for its con- 

 tinuance, since organisms are known which will bear 

 the loss of the greater part if not the whole of the 

 water they contain without permanent impairment of 

 their vitality. The presence of certain inorganic salts 

 is no less essential, chief amongst them being chloride 

 of sodium and salts of calcium, magnesium, potassium, 

 and iron. The combination of these elements into a 

 colloidal compound represents the chemical basis of 

 life ; and when the chemist succeeds in building up 

 this compound it will without doubt be found to 

 exhibit the phenomena which we are in the habit of 

 associating with the term "life."'-' 



Source of Life. The Possibility of Spontaneous 

 Generation. 

 The above considerations seem to point to the con- 

 clusion that the possibility of the production of life — 

 i.e., of living material — is not so remote as has been 

 generally assumed. Since the experiments of Pasteur, 

 few have ventured to affirm a belief in the spontaneous 

 generation of bacteria and monads and other micro- 

 organisms, although before his time this was by many 

 believed to be of imiversal occurrence. My esteemed 

 friend Dr. Charlton Bastian is, so far as I am aware, 

 the only scientific man of eminence who still adheres 

 to the old creed, and Dr. Bastian, in spite of numerous 

 experiments and the publication of many books and 

 papers, has not hitherto succeeded in winning over 

 any converts to his opinion. I am myself so entirely 

 convinced of the accuracy of the results which Pasteur 

 obtained — are they not within the daily and hourly 

 experience of everyone who deals with the sterilisation 

 of organic solutions? — that I do not hesitate to believe, 

 if living torulje or mycelia are exhibited to me in 

 flasks which had been subjected to prolonged boiling 

 after being hermetically sealed, that there has been 

 some fallacy either in the premisses or in the carrying 

 out of the operation. The appearance of organisms in 

 such flasks would not furnish to my mind proof that 



9 The most recent ."iccount of the chemistry of protoplasm is that hy 

 I)ot.-izzi(" DasCytopbsma u. die KBrpersafic ") in Winter-tein's " Han.lb. 

 ", Physiologic," Rd. I., T012 The literature is given in this article. 



NO. 2236, VOL. 90] 



they were the result of spontaneous generation. Assum- 

 ing no fault in manipulation or fallacy in observa- 

 tion, I should find it simpler to believe that the germs 

 of such organisms have resisted the effects of pro- 

 longed heat than that they became generated spon- 

 taneously. If spontaneous generation is possible, we 

 cannot expect it to take the form of living beings 

 which show so marked a degree of differentiation, both 

 structural and functional, as the organisms which are 

 described as making their appearance in these experi- 

 mental flasks.'" Nor should we expect the spontaneous 

 generation of living substance of any kind to occur in 

 a fluid the organic constituents of which have been 

 so altered by heat that they can retain no sort of 

 chemical resemblance to the organic constituents of 

 living matter. If the formation of life — of living sub- 

 stance — is possible at the present day — and for my 

 own part I see no reason to doubt it — a boiled infusion 

 of organic matter — and still less of inorganic matter — 

 is the last place in which to look for it. Our mistrust 

 of such evidence as has yet been brought forward 

 need not, however, preclude us from admitting the 

 possibility of the formation of living from non-living 

 substance." 



Life a Product of Evolution. 



Setting aside, as devoid of scientific foundation, the 

 idea of immediate supernatural intervention in the first 

 production of life, we are not only justified in believing, 

 but compelled to believe, that living matter must have 

 owed its origin to causes similar in character to those 

 which have been instrumental in producing all other 

 forms of matter in the universe; in other words, to a 

 process of gradual evolution.'- But it has been cus- 

 tomary of late amongst biologists to shelve the in- 

 vestigation of the mode of origin of life bj' evolution 

 from non-living matter by relegating its solution to 

 some former condition of the earth's history, when, 

 it is assumed, opportunities were accidentally favour- 

 able for the passage of inanimate matter into animate ; 

 such opportunities, it is also assumed, having never 

 since recurred and being never likely to recur. '^ 



Various eminent scientific men have even supposed 

 that life has not actually originated upon our globe, 

 but has been brought to it from another planet or 

 from another stellar system. Some of my audience 

 may still remember the controversy that was excited 

 when the theory of the origin of terrestial life by the 

 intermediation of a meteorite was propounded by Sir 

 William Thomson in his Presidential Address at the 



1" It is fair to point out that Dr. Baslian suggests that the formation of 

 ultraniicroscopic living particles may precede the appearance of the micro- 

 scopic organisms which he descril)es. " The Origin of I ife," tqir, p. 65. 



n The present position of 'he suhject is succinctly stated by Dr., Chalmers 

 Mitchell m his article on " Abiogenesis" in the " Encyclopardia Britannica." 

 Dr. Mitchell adds : *' It ma- he that in the progress of science it may yet be 

 possible to construct living protoplasm from non-living material. The refuta- 

 ti"n of abiog<*nesis has no fu'ther hearini; on this p >ssihility than to make it 

 probable that if protoplasm ultitnatelv be formed in the laboratory, it will be 

 bya seiies of steps, the earlier steps being the formation of some substance, 

 or substances now unknown, which are not protoplasm. Such intermediate 

 stages may have existed in tht^ pa-^l." And Htixley in his Presidential 

 Address at Liverpool in 1870 savs : " Hut though I cannot express this con- 

 viction" (I'u:, of the impossibility ol the occurrence of abio2enesis as 

 exemplified by the appearnnre ol orgai.isms in herinetirally sea'ed and 

 sterilised flasks) '-too strongly, I must ca'efully guard myself against the 

 suppovition that I intend to -ugyest that no such thing as abiogenesis ever 

 has taken place in the past or ever will take place in the future. With 

 organic chemistry, molecular phy>ics atid physiology yet in their infancy and 

 evtry day makitig prodigious strides, I think it would he the height of 

 presttmption for any man to say that the conditions under which_ matter 

 as-umes the properties we call "vital" may not, some day, be aitificialty 

 brought together." 



1'- The argttments in favour of this proposition have been arrayed by 

 Meldola in his Herbert Spencer Lecture, 1910, pp. i6-?4. Meldola leaves 

 the question open whether such evolution has occurred only in past years or 

 i- also taking p'are now. He concludes that wher.'as certain carbon com- 

 pounds have survived by reason of possessing extreme stabili'y, others — the 

 prerur-ors of living matter survived owing to the possession of extreme 

 lability ard ar'aptability to variable conditions of environment. A similar 

 sutigestion was previously made by I ockyer, ," Inorganic Evolution," 1900, 

 pp. i6g, 170. 



1:1 T. H. Huxley, Presidential Address, 1870; A. B. Macallum, "On the 

 .Origin of Life on the Globe," in Trans. Canadian Institute, VI 11. 



