386 GREAT STEPS IN ORGANIC EVOLUTION 



covery of electro-magnetism, magnets were made from mag- 

 nets. And until recently crystals were obtained in a crystal- 

 lisable solution only by the introduction of a nucleus of 

 crystallisation. Thus melted salol, protected from crystals 

 of any kind, remains liquid indefinitely in a closed tube. 

 If it be touched with a platinum wire that has been in 

 contact with solid salol, crystallisation sets in, because a 

 nucleus has been introduced. If the wire be heated first its 

 introduction is without effect. But in 1867, as Professor 

 Dastre (1911) points out, crystals of glycerine appeared 

 spontaneously in glycerine, and have since been spread 

 throughout Europe. No one knows the circumstances which 

 determined their formation, and if they became extinct, as 

 might readily happen, no one knows how to produce them 

 again. In the same way, — this is Professor Dastre's pertinent 

 argument, — the fact that within our knowledge living organ- 

 ism always springs from similar living organism, and that no 

 spontaneous generation of any microbe has ever been dem- 

 onstrated in any culture-medium, does not warrant us in mak- 

 ing a dogma of omne vivum e vivo. 



Prof. Lloyd Morgan's position in regard to the origin 

 of living organisms is one that commends itself. " Of pro- 

 toplasm we may likewise say that under certain conditions, 

 at present unknown, it appeared. Those who would con- 

 centrate the mystery of existence on the pin-point of the 

 genesis of protoplasm do violence alike to philosophy and 

 to religion. Those who would single out from among the 

 multitudinous diiferentiations of an evolving universe this 

 alone for special interposition would seem to do little honour 

 to the Divinity they profess to serve. Theodore Parker gave 

 expression to a broader and more reverent theology when 

 he said : " The universe, broad and deep and high, is a hand- 



