3Q2 THE POPULAR SCIENCE MONTHLY 



fashioned animal breeders, the advantage of the new methods over the 

 old must be apparent. Instances of this kind give us good reason for 

 believing that before many years have passed useful forms of animals 

 and plants will be produced on demand, not in the somewhat haphazard 

 way of the present practise of breeders, but with the certainty and pre- 

 cision with which a modern inventor constructs a new piece of 

 machinery. 



This change in the aspect of evolutionary matters can not be better 

 illustrated than by three quotations that preface one of the most impor- 

 tant publications on evolution in the last decade, " Species and Varie- 

 ties, their Origin by Mutations." The quotations, which are arranged 

 in historical sequence and come from the three great masters in this 

 field, are as follows : 



The origin of species is a natural phenomenon. — Lamarck. 



The origin of species is an object of inquiry. — Darwin. 



The origin of species is an object of experimental investigation. — De Vries. 



The last statement, that the origin of species is open to experimental 

 study, is the keynote to modern evolutionary work. But it is not simply 

 the keynote to this particular part of biology ; it marks a change in front 

 of the whole army of biological workers whereby the science of the 

 organism is being transformed from one of observation pure and simple 

 to one which includes experiment. "We sometimes hear astronomy, 

 chemistry, physics, etc., described as the exact sciences, and our friends 

 in these domains of knowledge occasionally take a hidden pleasure, I 

 suspect, in intimating that what lies outside their realm, including biol- 

 ogy, must belong to the inexact category. That biology has not been 

 exact in the sense that physics and chemistry have been, we freely admit, 

 but physics was not always exact, and before the days of Lavoisier, 

 chemistry had few quantitative results of which it could boast. Biology, 

 from the nature of the materials it has had to master, has of necessity 

 been slow in growing to that stage where it was imperative to use those 

 refined methods that have long been employed by physics and chemistry. 

 But these methods are rapidly being assimilated by the more progressive 

 members of the biological fraternity, who are discovering that there is 

 nothing inherently inexact about the subject-matter of biology or its 

 treatment. This subject-matter is open to the same searching method 

 as is that of the so-called exact sciences. But though we are not yet 

 admitted to full fellowship with these sciences, we are at least the center 

 of the observational group and, if we wished to retaliate on our good 

 friends of the exact sciences, we might declare them non-observational 

 with as much reason as they call us inexact. But you will accuse me of 

 falling into a word controversy. And such it would be. The truth is 

 that biology is rapidly becoming experimental, and in doing so it neces- 

 sarily assumes all those methods and procedures that have long been 



