312 . Professor William J. Pope [^iay 1, 



Acting uniutelligently or fortuitously, one half of the individuals 

 would become dextro-beings whilst the other half would become 

 lasvo-indivifluals ; the succeeding generations would thus be of two 

 enantiomorphously related configurations. It is, however, very 

 difficult to believe that the natural selective operations which have 

 been instrumental in conducting living organisms to their present 

 stage of development, would allow the perpetuation of this state of 

 affairs for any considerable period ; some fortuituous enantiomorphous 

 occurrence would temporarily give the one configuration the advantage 

 over the other, an advantage which would be quickly accentuated 

 and would involve the permanent disappearance of the weaker con- 

 figuration. 



The kind of difficulties involved in the existence, side by side, of 

 individuals of dextro- and of laavo-tendencies, may be shown by a 

 simple illustration. There is no reason connected with human enan- 

 tiomorphism why vehicular traffic should be forced to keep to one 

 side of the road rather than to the other ; as, however, the conditions 

 of civilised life have gradually become more complex, economic reasons 

 have arisen forcing us to make an enantiomorphous selection and 

 in this country we arbitrarily force the traffic to keep to the left ; other 

 countries also make an arbitrary, and sometimes a different, selection. 

 Even if, when legislation on this matter first became necessary, the 

 population had been equally and obstinately divided upon the question 

 of the rule of the road, we cannot doubt that by this time the difficulty 

 would have been satisfactorily and finally settled by the extermination 

 of one or other of the enantiomorphously inclined parties without the 

 co-operation of any intelligent enantiomorphous agency. 



I mentioned that Pasteur gave a third method for the resolution 

 of compensated substances, a method depending upon the selection 

 exercised by living organisms upon the enantiomorphously related 

 components of the mixture. He found, for instance, on allowing the 

 mould Penicillium glaucum to grow in a solution containing com- 

 pensated tartaric acid, that the mould used the d-tartaric acid as a 

 food- stuff and rejected the Isevo-isomeride, wbich latter could ulti- 

 mately be separated from the solution. The kind of method thus 

 indicated has been applied with success in a great number of cases, 

 and is, in the end, merely a special application of Pasteur's second 

 method. During recent years a considerable change has taken place 

 in our views concerning the action of the lower organisms upon their 

 food-stuffs. It was formerly supposed, for example, that the fermenta- 

 tion of sugar by an ordinary beer yeasi is a part of tlie vital process 

 of the organism itself, that the sugar taken in as food by the organism 

 is finally thrown out in the form of carbon dioxide and alcohol ; it is 

 now clear, however, that the formation of these two products is in no 

 way a vital process. On triturating yeast with powdered quartz so 

 as to shatter the cell walls, and expressing the pulp thus produced, 

 Buchner succeeded in obtaining a solution which, when mixed with 

 sugar solution converts the sugar into carbon dioxide and alcohol. 

 This fermentation is therefore not a vital phenomenon but is a 



