SCIENCE 



Friday, December 19, 1913 

 contents 



On the Nature of Mathematical and Scientific 

 Demonstration: Professor E. D. Cae- 

 MICHAEL 863 



BeooUections of Dr. Alfred Bussel Wallace: 

 Professor T. J). A. Cockerell 871 



Scientific Notes and News 877 



University and Educational News 880 



Discussion and Correspondence: — 

 More Paleolithic Art: Professor George 

 Grant MacCurdt. On Interference Colors 

 in Clouds: Dr. Egbert H. Goddasd. Origin 

 of Mutations: Professor E. A. Emerson. 

 How Oryctes rhinoceros uses its Horns: E. 

 W. DoANE. Science and the Newspaper: 

 Professor Francis E. Nipher. The In- 

 dustrial Fellowships at Pittsburgh: J. F. 

 Snell 881 



Scientific BooTcs: — 



WiUstaetter and Stall's UntersuchMngen 

 iiher Chlorophyll: E. K. Wilson on the 

 Principles of Stoch-ireeding : H. H. Laugh- 

 LIN. Herbert on Evolution: J. P. McM. . . 884 



Special Articles: — 



On Fundamental Methods of Orientation 

 and "Imaginary Maps": Professor C. C. 

 Trowbridge 888 



The Convocation Weelc Meeting of Scientific 

 Societies 897 



Societies and Academies: — 



The Botanical Society of Washington: P. 

 L. ElCKER. The Philosophical Society of 

 the University of Virginia: L. G. Hoxton. 899 



M8S. intended for publication and books, etc., intended for 

 leview should be sent to Professor J. McEeen Cattell, Qarrison- 

 On-Hudson. N. Y. 



ON THE NATVBE OF MATHEMATICAL AND 

 SCIENTIFIC DEMONSTBATIOm 



In the development of every science 

 there is a growth of method as well as of 

 results. We are accustomed to give close 

 attention to the latter, and frequently we 

 reorganize them into connected and logical 

 wholes so that every student may conveni- 

 ently view them in their entirety and in 

 their proper relations to one another. In 

 determining the method by which the mat- 

 ter shall thus be organized we are generally 

 guided by considerations of convenience 

 in exposition. 



In much of our teaching, likewise, the 

 selection and arrangement of material is de- 

 termined primarily by a desire to arrive at 

 results in the most expeditious manner 

 possible. 



One effect of this controlling emphasis, 

 both in lecturing and in the writing of 

 books, is that many of us never come to a 

 proper appreciation of the labor which has 

 been expended in perfecting our tools of 

 investigation and never have a vital con- 

 ception of the character of the important 

 problem of method. Such a person usually 

 will be able to employ only the tools which 

 are presented to him by others. He will 

 not be able to devise a new method to 

 meet the needs of the new problem which 

 arises in his own work. 



Now the most important steps forward 

 are made by the introduction of new 

 methods of advancement. It is obvious 

 that the person most likely to discover the 



1 An address delivered on the evening of Oc- 

 tober 6, 1913, to "The Euclidean Circle," an or- 

 ganization among the graduate and undergraduate 

 students of mathematics in Indiana University. 



