226 



THE POPULAR SCIENCE MONTHLY 



Fig. 1. A Typical Maize Plant as 



DESCRIBED BY THE BOTANISTS. (After 



Bonafous.) 



Fig. 2. A Reproduction of the 

 Chinese Drawing upon which Rested 

 the Argument for Asiatic Origin of 

 Maize. (After Bonafous.) 



of the botanical historian and has been carried further than that of any 

 other plant that has been cultivated since before recorded time and of 

 which the wild prototype is unknown. 



The clues upon which the botanical detective works are many, and 

 it is only by dovetailing numerous facts that the probability of a correct 

 conclusion is increased until it is beyond question. That criminal de- 

 tectives can establish a reasonable proof by circumstantial evidence was 

 shown long ago by Poe. Mathematics does not recognize a series of 

 coincidences. Coincidences do occur but not in series. If a series of 

 facts point to the same conclusion, the probability that that conclusion 

 is correct increases by multiplication, not by addition. If the probabil- 

 ity that one throws heads with a coin is one half, the probability that he 

 throws a pair of heads with two coins is one half times one half, or one 

 quarter, not one half plus one half which would be a certainty. Thus 

 the fictitious reasoners of Poe and Doyle have argued that if a series of 

 independent circumstances point in a single direction, that direction is 

 the proper one. If certain facts seem to be outstanding, they must be 

 looked to, for their fallacies will sooner or later come to light. The 

 same is true in botanical history as the following incident shows: 



