100 THE PROBLEM OF EVOLUTION 



certainly follows that it was composed of them, 

 but it does not follow that it came into existence out 

 of them spontaneously. Otherwise a house, which 

 is pulled down and becomes merely a heap of 

 bricks, ought to have come into existence 

 automatically out of a heap of bricks. Thirdly, 

 Plate refers to the alleged transitions between 

 organic and inorganic substances. Solid 

 crystals show no such transitions, for they aim 

 at stable equilibrium of their molecules, as 

 opposed to the unstable equilibrium of the 

 molecules in living beings. Lehmann's famous 

 liquid crystals do not supply us with the 

 desired proof. The resemblance between their 

 movements and those of the lowest organisms 

 is purely superficial, and rests merely on 

 chemical and physical modifications. Our 

 imagination may lead us to speak of these 

 formations as devouring one another, as having 

 sexual intercourse with one another, and so 

 on, but we cannot use these expressions in 

 their literal sense. I shall refer to this subject 

 more in detail in my closing speech and in the 

 remarks upon it. 



What Plate calls c ascertained facts ' do not 

 therefore furnish us with any satisfactory 

 scientific basis for the hypothesis of spon- 

 taneous generation. When he describes the 

 assumption of a creation as a ' comfortable 

 solution,' which he as a scientist is unable to 



