THE PLANT WORLD. 
2 56 
some affair. This can be avoided. More than that, experimental 
work can be so managed that it will satisfactorily meet the present 
objections—the expensive apparatus demanded and the great 
length of time necessary to acquire even a little knowledge at 
first hand. 
Work in grammar and high school classes during the past two 
years has shown great gain when directions were not given but 
the question put directly to the class, is: 
Has air weight? Is liquid pressure the same at all depths? 
Do plants breathe as animals do? What influence does light 
have upon stems? What part of the plant gives out water? 
The opinions advanced by various pupils were discussed. Sides 
were taken, often. Next followed the questions, “ How can we 
find out? ” or “ How can you prove that is true? I don’t believe 
it.” Then, from the pupils came the directions for the experi¬ 
ment—some workable—others not, but by the time the directions 
suited the majority of the class they were usually in surprisingly 
good form. Often initial statements were given by the teacher, 
as the effect of the breathing of animals on pure lime water in 
answering part of the third question above given. The rest was 
left to the class. “ That will keep out the light but not the air,” 
“ You’ll have to seal it or more oxygen can come in,” “ That 
won’t be fair, for it has less air than the plant in the light,” 
“ That won’t prove it unless you weigh it before and after, both,” 
“ That won’t show that the stem doesn’t give out water, too,” are 
a few of the criticisms by the pupils: At last, one or two mem¬ 
bers of the class set up the experiment and when ready reviewed 
the question and the method, and interpreted the results. If the 
result is surprising, a text-book is consulted; should there be a 
difference the experiment is gone over carefully to see whether 
the book is wrong or whether some joint has not been made air 
tight; whether the water supply proved insufficient for full de¬ 
velopment, etc., and the experiment is made again under the im¬ 
proved conditions. A boy in one class found to his surprise that 
seeds grow better when left with but half of the food material. 
The class refused his results at once, pointing out that he had 
used soil for the various seeds, and that it was unequal in amount 
and moisture. 
