THE ORIGIN OF LIFE ARMSTRONG. 531 



phur. At some early period, however, the possibilities became limited and directed 

 processes became the order of the day. From that time onward the chemistry pre- 

 vailing in organic nature became a far simpler chemistry than that of the laboratory; 

 the possibilities were diminished, the certainties of a definite line of action were 

 increased. How this came about it is impossible to say; mere accident may have led 

 to it. Thus we may assume that some relatively simple asymmetric substance was 

 produced by the fortuitous occurrence of a change under conditions such as obtain 

 in our laboratories and that consequently the enantiomorphous isomeric forms of equal 

 opposite activity were produced in equal amount. We may suppose that a pool 

 containing such material haAOJig been dried up dust of molecular fineness was dis- 

 persed; such dust falling into other similar pools near the crystallization point may 

 well have conditioned the separation of only one of the two isomeric forms present in 

 the liquid. A separation ha-\dng been once effected in this manner, assuming the sub- 

 stance to be one which could influence its own formation, one form rather than the other 

 might have been produced. An active substance thus generated and selected out 

 might then become the origin of a series of asymmetric syntheses. How the compli- 

 cated scries of changes which constitute life may have arisen we can not even guess 

 at present; but when we contemplate the inherent simplicity of chemical change 

 and bear in mind that life seems but to depend on the simultaneous occurrence of a 

 series of changes of a somewhat diverse order, it does not appear to be beyond the 

 bounds of possibility to arrive at a broad understanding of the method of life. Nor 

 are we likely to be misled into thinking that we can so arrange the conditions as to 

 control and reproduce it; the series of lucky accidents which seem to be required 

 for arrangements of such complexity to be entered upon is so infinitely great. 



It is permissible now, perhaps, to enter somewhat more at length 

 into an explanation of the changes contemplated in this passage. 



Growth most certamly proceeds on detennined lines — "directive 

 influences are the paramount influences at work in building up livuig 

 tissues" (Wiimipeg address). Wliat Prof. Schafer has not pointed 

 out, in contrasti]ig the growth of htorganic and of animal matter, is 

 that nature now works on very narrow Imes, makmg use of but little 

 of the wealth of material primarily at her disposal. Selective influ- 

 ences must have been at woik from the earliest stages of the evolu- 

 tion of life onward. It is in this respect, perhaps, more than any other 

 that the inorganic differs so greatly from the organic; it is this cir- 

 cumstance, too, more than any other which makes it so improbable 

 that life should arise frequently de novo from simple materials not 

 themselves the products of vital action. 



To give an example, the licxosc, glucose — a constituent of every 

 plant and animal — is one of 16 isomeric compounds, all represented 

 by the fomiula 



CH2(0H). CH(OH). CH(OH). CH(OH). CH(OH). COH. 



Of these 16 compounds, 14 have actually been prepared in the labo- 

 ratory, and they differ considerably in properties. Tho differences 

 are due to the different distribution in space of the TI and OH groups 

 relatively to the carbon atoms. Tho 16 compounds fonn 8 pairs, and 

 as the individual members of each pair have the power of rotating 



