TO THE STUDENT. 



You are beginning the* study of living things, and it is 

 very important that you should begin in the right way. 

 These practical exercises are intended to help you, but not 

 to do the work for you. Many of the exercises will seem 

 very simple, but if you actually do what is called for, it 

 will be plain why so much stress is laid on knowledge 

 gained by direct personal observation and experiment. 1 



There are a few things that you ought to consider at the 

 outset. 



1. First of all, it is essential that you should learn to 

 see things just as they are, and to report exactly what 

 you have seen. Agassiz used to say to his students: 

 "Study to know what is; be courageous enough to say 

 4 1 do not know.' " Tyndall said to the teachers at South 

 Kensington : " In every one of your experiments endeavor 

 to feel the responsibility of a moral agent. ... If you 

 wish to become acquainted with the truth of Nature, you 

 must from the first resolve to deal with her sincerely." 

 Darwin in his autobiography 2 writes: " I had during many 



1 " You wish, for example, to get a knowledge of magnetism ; well, pro- 

 vide yourself with a good book on the subject, if you can, but do not be 

 content with what the book tells you ; do not be satisfied with its 

 descriptive woodcuts ; see the actual thing yourself. Half of our book- 

 writers describe experiments which they never made." TYNDALL, Frag- 

 ments of Science. 



2 Life and Letters, p. 71. 



ix 



