January 9, 1914] 



SCIENCE 



55 



sible in a comparatively brief period of 

 time to make the student of physiology ac- 

 quainted with the fundamental conditions 

 which disturb the circulation of the blood, 

 for he creates the disturbance at will; it 

 would take years to show him the same 

 things on patients, because the lesions must 

 be taken a;t random as the cases present 

 themselves in the clinic. 



It has been asserted that the mammalian 

 experiments at least should be merely dem- 

 onstrated to the students and that they 

 themselves should not be called upon to 

 participate in them. It has been pointed 

 out, for example, that the fact that two 

 loads are of equal weight is no more con- 

 vincingly demonstrated by one's actually 

 placing the loads on the scale pans of the 

 balance than by seeing this done by an- 

 other person. But the difference between 

 this and a physiological experiment is very 

 very great, and furnishes the very reason 

 for which the latter should be performed 

 by the student himself. For this differ- 

 ence depends on the fact that we are deal- 

 ing with living processes that may mate- 

 rially alter the result of the experiment 

 unless they are adequately controlled; to 

 learn how to control them is one of the 

 most important things that the student of 

 medicine can learn. It would go beyond 

 the scope of this article to present other 

 arguments for or against the inclusion of 

 practical work on mammals in the physi- 

 ology course, but there is one pedagogical 

 criticism that sometimes is made against 

 the experiments that should be taken no- 

 tice of. This refers to the possibility that 

 the student may lose sight of the object 

 for which the experiment is being per- 

 formed on account of the attention which 

 he must give in order to overcome the 

 •technical difficulties which it involves. 

 This is undoubtedly likely to be the case 

 unless great care is taken to have each ex- 



periment preceded by a conference, and, 

 after several have been performed, to have 

 the results reported and discussed in semi- 

 nars. It is true that it may not be pos- 

 sible for the student immediately to cor- 

 relate and place their full meaning on the 

 experimental results which he obtains, and 

 for this reason the teacher should as fre- 

 quently as posvsible refer to these results 

 in illustration of the principles which he is 

 endeavoring to unfold in the didactic 

 courses. Ultimately, however, the obser- 

 vations which he himself has made come to 

 furnish the mainstay of the student's 

 physiological knowledge, and he uses them 

 as the basis for his further development. 



Eight to ten sessions of four hours each 

 are required for the mammalian experi- 

 ments, after which several sessions are oc- 

 cupied in making accurate observations on 

 the physiological functions of normal men, 

 one student in each group serving in turn 

 as the subject of investigation. In recent 

 years the methods available for studies of 

 this nature have very materially multi- 

 plied, indeed have done so to such an ex- 

 tent that several of the fundamental prin- 

 ciples of physiology can now be as ade- 

 quately demonstrated on man as by experi- 

 ments on the lower animals. This permits 

 of a certain amount of displacement of the 

 experiments on anesthetized animals, an 

 object which, for various reasons, should 

 always be kept in view. 



Coming now to the place of the didactic 

 instruction, it may in general be stated 

 that tliis should be so arranged as to sup- 

 plement the practical. The lecture and 

 recitation are certainly is indispensable as 

 the practical class, for in them the princi- 

 ples of physiology — the institutes of medi- 

 cine — must be expounded in logical se- 

 quence, and, as has already been stated, 

 the bearing of the experiments which the 

 students themselves have performed must 



