The Message of Science. 17 



plasm, year by year, than during the present era. From 

 age to age the quantity has varied in accord with the 

 terrestrial conditions. 



As yet we know no method of transmuting non-living 

 into living matter apart from the agency of previously 

 existent living matter. But no more can we at present 

 make feldspar, or mica, or gold, or silver, or lead. It is 

 as likely that we shall discover a method of producing 

 living matter, as that we shall learn to produce any of 

 these substances. The task waits a deeper knowledge of 

 matter, but is impossible only for the present. 



One reason for believing that new protoplasm and new 

 protozoa no longfir come^ into existence spontaneously, is 

 that many or all of the micro-organisms which we study 

 under the microscope are new only in the sense of being 

 newly discovered by us. Many of the disease-bacteria 

 were at least operative and produced the same poisons 

 three thousand years ago. The diatomacese of to-day ex- 

 hibit the same characteristics and the same silicious enve- 

 lope as those taken from fossiliferous strata laid down in 

 the seas of the tertiary epoch. In fact, many of the gen- 

 era of micro-organisms are the most venerable and change- 

 less of any upon the earth. Nor can we wholly agree with 

 those who regard these minute creatures as the most rudi- 

 mentary of living forms. It by no means follows that be- 

 cause a living creature is small, that it is hence exceedingly 

 simple and recent in the sense of ancestry and heredity. 



