January 7, 1910] 



SCIENCE 



I have used the phrases lines of inductive -force 

 and curved limes of force in a general sense only, 

 just as we speak of lines of magnetic force. 



He does not represent field intensity by 

 lines. 



Maxwell, however, changed the meaning 

 by calling Faraday's lines of force lines 

 of induction and using the term lines of 

 force for lines of intensity only. 



tA.nd we 1 We use the words sometimes in 

 Faraday's sense, sometimes in Maxwell's 

 sense. We introduce them when speaking 

 of field intensity and later on make the 

 glaring mistake of asserting that the in- 

 duced electromotive force is measured by 

 the cutting of lines of force. The Ameri- 

 can Institute of Electrical Engineers has 

 proposed to call the unit of magnetic in- 

 tensity the "gauss"; it seems to be a gen- 

 eral understanding, judging from papers 

 appearing on magnetic subjects, that it is 

 also the unit of induction. Personally I 

 prefer to discard the troublesome term al- 

 together, but it may be that it has become 

 so familiar to the scientist and is so gen- 

 erally used in engineering practise, though 

 usually there in the meaning of lines of 

 induction, that it is too late to abolish it 

 altogether. If we must keep the lines 

 of force in our text-books, let us use them 

 in one sense only. We should certainly 

 stop confusing our students about the real 

 nature of these two totally different quan- 

 tities.^ 



I hope to have proven that we lack in 

 the presentation of several topics that ac- 

 curacy of expression of which in general 

 the physicist can be justly so proud, and 

 that greater iiniformity in the use of cer- 

 tain terms is very desirable. Our ideas as 

 to the fitness of proposed names for the 

 quantities in question as well as to the 

 choice of definitions, may be widely differ- 

 ent. Your speaker clearly realizes that 



° See also a paper by Professor Patterson, 

 "Michigan Teehnie," 20, No. 2, p. 35, 1907. 



there is ample room for discussion and that 

 the sporadic attempt of a single scientist 

 to correct the apparent faults in our teach- 

 ing can not better the conditions appreci- 

 ably. 



Reforms of a lasting nature can be ac- 

 complished and the desired result reached 

 in shortest time, only, if definite proposi- 

 tions be made by a committee consisting of 

 a number of representative physicists. 

 With their influence behind a reform 

 movement of this kind we shall soon reach 

 practical unanimity. 



In conclusion, let me assure you from 

 my own experience that it is not an ex- 

 tremely difficult matter to teach the stu- 

 dent to make these fine distinctions between 

 different physical qiiantities. It is true, it 

 requires some deep and accurate thinking; 

 but the result has always been that in the 

 end the subject has become clearer to the 

 student and, as I have been assured, even 

 more interesting. 



K. E. GUTHE 



J 

 TEE EVOLUTION OF INTELLIGENCE AND 



ITS ORGANS '^ 



We recognize two very distinct types of 

 physiological functions: (1) activities con- 

 cerned with the inner working of the bodily 

 mechanism — nutrition, internal regulation, 

 etc. — and called vegetative or visceral func- 

 tions; (2) activities concerned with the 

 adjustments of the body to outside, or 

 environmental influences. These we call 

 somatic functions. 



These reaction types are, of course, al- 

 ways intimately related and interdepend- 

 ent; nevertheless, as we ascend the scale 

 of animal life the history of the evolution 

 of both structure and function shows a 

 progressive elaboration of each of these 



" Address of the vice-president and chairman of 

 Section F — Zoology. American Association for 

 the Advancement of Science, Boston, 1909. 



