6 8 THE NA TURE-S TUB Y RE VIE W U ■ 2-fbbruary, 1906 



arithmetic, are easily capable of gradation, especially by the sub- 

 division of the subject-matter. A special period of the history of 

 one nation, the geography of a certain state or # continent, the writings 

 of certain authors, particular arithmetical manipulations — these suggest 

 the ease of differentiating and grading the common subjects. 



Such sub-division is not possible in physiology. All the functions are 

 so bound together in interdependence that no logical grading can be 

 made by studying digestion in one year, circulation in another, and so 

 forth. This method of grading " physiology" by dividing it into as 

 many topics as there are years is in use in some schools, but such 

 a method is unfortunate because it must fail to teach the mutual rela- 

 tionship of organs in the body as a working whole, and consequently 

 physiological facts are bound to stand more or less unrelated in the 

 minds of the pupils. I fail to find that any prominent teachers of 

 physiology or any specialist in the science has approved such sub- 

 division of the science. 



Likewise in teaching any one of these functions it is not possible to 

 make gradation of the facts which are important in general education. 

 For example, it is taught as a simple fact in intermediate grades that 

 the stomach secretes gastric juice which prepares proteid foods for 

 absorption. In the next book for upper grammar grades the infor- 

 mation that certain constituents, pepsin, etc., of gastric juice are con- 

 cerned in the digestion of proteids is added. Finally in the high 

 school some supplementary details regarding the chemical conditions 

 and changes are given. It is evident to experienced teachers of 

 physiology that the elementary statement in the intermediate grade 

 and a single laboratory demonstration give the knowledge of proteid 

 digestion which is most important in general elementary education ; 

 and the additional facts are details of little value and interest to the 

 pupils below college. 



Parallel illustrations might be drawn from the study of any other 

 function, and it could be made just as clear that so far as the essen- 

 tial principles of physiological activity are concerned the subject- 

 matter does not admit of satisfactory grading in a series of books. 

 A large amount of unnecessary repetition of the essential facts is 

 unavoidable, for the important points which pupils will remember 

 are commonly presented as clearly in the "elementary" as in the 

 " high-school " text-book of " physiology." 



Such repetition is especially likely to be wearisome when physiology 

 is presented by teachers who are not specially trained for the work. 



