3^3 



particular compound were one, ammonium carbonate, and all 

 the other materials of diverse composition from which Dr. 

 Bastian believes life to be evolved, could not be isomeric as 

 well. 



Evolution must be consistent with itself. A truly monistic 

 conception of iiatuie, to use Haeckel's word, repudiates the 

 spontaneous appearance of life, as it repudiates everytbing 

 else spontaneous ; but it implies the continuity of what is 

 living with what is lifeless, of what is called vital with what 

 is called physical. The evolution of proteinaceous matter, as 

 Mr. Spencer observes, must have taken place in the early 

 world according to the same laws as those to which chemists 

 have unconsciously conformed, and it is impossible to indicate 

 more clearly than in his words the further changes Avhich, in 

 harmony with general modes of evolution, this proteinaceous 

 matter must have undergone. 



'' Exposed," he says, " to those innumerable modifications 

 of conditions which the earth's surface afforded, here in 

 amount of light, there in amount of heat, and elsewhere 

 in the mineral quality of its aqueous medium, this extremely 

 changeable substance must have undergone, now one, now 

 another, of its countless metamorphoses. And to the mutual 

 influences of its metamorphic forms, under favouring condi- 

 tions, we may ascribe the production of the still more compo- 

 site, still more sensitive, still more variously changeable 

 portions of organic matter, whichj in masses more minute 

 and simpler than in existing Protozoa, displayed actions 

 verging little by little into those called vital — actions which 

 protein itself exhibits in a certain degree, and which the 

 lowest known living things exhibit only in a greater de- 

 gree." 



It is evident that vdiat is here described requires an ampli- 

 tude in the range and varieties of the conditions Avhich could 

 not possibly be realised in an experiment. It becomes, in 

 fact, almost as difficult in such conceptions to imagine the 

 evolution of a new plant species in a flower-pot as life in a 

 scaled flask. 



Dr. Bastian's first observations deal with the changes of the 

 so-called " proligerous pellicle " of Burdach, and he certainly 

 does not overstate the opposition to " generally received 

 biological notions " involved in the transformation of aggre- 

 gations of monads and bacteria into larger and higher kinds 

 of living things. His description of the way this takes place 

 is, however, very materially different from that Avhich has 

 been given by other Avriters, and the difference consists, not 

 ' ' Principles of Biology/ vol. i, App., pp. 483, 484. 



