26 THE BEGINNINGS OF LIFE. 



colloid molecules combine and undergo molecular re- 

 arrangements leading to the formation of those insoluble 

 compounds which separate from the solution in the 

 form of specks of living matter, we can only give ex- 

 pression to our profound ignorance on the subject. At 

 the same time, however, we can express only the 

 same ignorance as to the reason why any of the other 

 more simple chemical changes occur, as it were spon- 

 taneously. The fact that the new products do make 

 their appearance in the latter set of cases, leaves no 

 doubt as to the conclusion that they have originated 

 by molecular rearrangements which have taken place 

 amongst the pre-existing elements. And in the face 

 of the evidence which has been adduced, it seems to 

 me almost equally certain that the organisms which 

 have been found in some of our flasks must have de- 

 veloped from specks of living matter, which had them- 

 selves originated from a molecular rearrangement and 

 combination occurring amongst the colloid molecules 

 of the solution. Just as the colloids themselves have 

 been produced as a result of the molecular interaction of 

 substances having a simpler composition, so may living 

 matter be produced through the molecular interaction 

 of colloids under the influence of heat and other physical 

 agencies. We cannot explain why such interaction 

 and molecular rearrangement should take place amongst 

 colloidal molecules, and there may be all the less room 

 for surprise at this when we reflect that we are equally 

 powerless to explain why even the most simple chemical 



