430 COSMIC rillLOSOPIIY. [pt. tt. 



in a way not yet explained, upon the directions in which they 

 have been exerted by aucestral organisms. In other words a 

 set of definite tendencies has been acquired during the slow 

 evolution of organic life ; and it may well be doubted that, 

 even in the case of the bacterium, a tendency toward the 

 formation of single or double nuclei can have been gained 

 during the evolution of a single generation of individuals. 

 For in colloidal matter, as such, there is no definite tendency 

 toward the formation of nuclear spots, such as are seen in 

 bacteria. It is a main characteristic of colloids, as contrasted 

 with crystalloids, not to have any specific form. It is, 

 therefore, hard to believe that, during the decomposition of 

 some saline liquid, the freed elements not only recombine 

 into a colloid, but even go so far as to take on the specific 

 shape of a bacterium or vibrio, When any such succession 

 of phenomena appears to occur, it clearly points to the 

 ill-understood but imperative fact of heredity through a 

 long past. 



Until this difficulty is either cleared away by trustworthy 

 deduction, or overridden by some crucial experiment, I do not 

 think that the advocates of " spontaneous generation " can be 

 said to have made out their case ; and such an abstruse ques- 

 tion is here opened that it is not likely soon to be settled. 



For the present, in representing to ourselves how life may 

 have originated upon the earth, we are reduced to a few most 

 general considerations. However the question may eventually 

 be decided as to the possibility of archebiosis occurring at 

 the present day amid the artificial circumstances of the 

 laboratory, it cannot be denied that archebiosis, or the origi- 

 nation of living matter in accordance with natural laws, must 

 have occurred at some epoch in the past. That life has not 

 always existed upon the earth's surface is certain; and the 

 following considerations will show that in its first appear- 

 ance there need not have been anything either sudden of 

 abnormal. 



