324  The  Teaching  of  Physiology. 
our  knowledge  has  advanced,  noting  the  marks  which  distinguish 
the  paths  which  have  been  trodden  successfully  from  those  which 
have  turned  out  to  be  "  no  thoroughfare."  Even  better  opportunities 
for  mental  training  than  those  which  the  lecture-room  presents  are 
afforded  by  the  recitation,  for  here  the  minds  of  the  teacher  and  the 
pupil  are  brought  most  closely  into  contact,  the  pupil's  difficulties 
are  appreciated  by  the  instructor,  and  the  point  of  view  of  the 
teacher  can  be  learned  by  the  pupil.  It  has  always  seemed  to  me 
that  no  higher  enjoyment  falls  to  the  lot  of  the  teacher  than  that 
which  he  experiences  when,  by  a  series  of  carefully  considered 
questions,  he  leads  his  pupil  onward  from  the  known  to  the  un- 
known, and  notes  the  gleam  of  intelligence  which  illumines  his 
countenance  as  a  subject,  previously  obscure,  becomes  clear,  as  a 
result  of  his  own  mental  operations  guided  by  his  teacher's  skillful 
questions.  It  thus  appears  that  no  monopoly  of  opportunities  for 
mental  training  can  be  claimed  for  the  laboratory  method  of  instruc- 
tion, while,  for  the  purpose  of  imparting  necessary  information,  lab- 
oratory work  must,  for  reasons  just  given,  be  supplemented  by 
didactic  instruction. 
Recognizing,  therefore,  the  importance  of  both  the  laboratory  and 
the  lecture  room  as  educational  agencies,  let  us  consider  what  should 
be  their  relation  to  each  other.  The  question  is  often  formulated 
thus :  Shall  the  experiments  illustrate  the  lecture  or  shall  the  lecture 
explain  the  experiments  ?  If  forced  to  decide  between  these  alter- 
natives, I  confess  that  I  should  be  inclined  to  choose  the  latter,  for, 
by  giving  precedence  to  the  experiments,  the  teacher  conforms  his 
instruction  to  the  law  of  growth  of  an  experimental  science.  There 
are,  however,  many  departments  of  physiology  in  which  the  experi- 
mental data  suited  for  elementary  laboratory  instruction  bear  so 
small  a  proportion  to  the  sum  total  of  the  knowledge  which  must  be 
imparted  to  the  student  that  the  didactic  instruction  necessarily 
assumes  the  more  important  position  and  the  lectures  cannot,  with- 
out a  forced  use  of  language,  be  described  as  explanatory  of  the 
experiments.  It  seems  to  me,  therefore,  that  the  wisest  course  at 
the  present  time  is  not  to  attempt  to  decide  between  the  two  above- 
mentioned  alternatives,  but  to  let  the  method  of  instruction  vary 
with  the  subject. 
In  thus  classifying  physiological  subjects  according  to  the  methods 
best  suited  for  teaching  them,  it  must  be  borne  in  mind  that  such  a 
