SCHLEIDEN in 



data, and only thence. It is not until considerable 

 advance has been made towards perfection that it is 

 safe to begin to inquire whether analogies exist between 

 itself and some other branch of natural science, and, if 

 so, what they are. The manner in which science is usually 

 pursued is not following it out gradually through a long 

 course of original investigations, but by grasping hastily 

 at all statements and dogmas that are afloat respecting 

 it, seeking to participate in its treasures as an inheritance 

 from strangers, rather than by examining into its founda- 

 tions and building up its structure ; this is the reason 

 that we find even more dangerous prejudices to combat 

 in science than in practical life. . . . Thus it has been with 

 Botany : books have been written when plants should 

 have been examined, conjectures have been made when 

 investigations should have been pursued. Hence for 

 about a century we have but revolved in a circle, without 

 making the least advance or discovering new facts ; and 

 new laws are given us which are only the result of the 

 play of chances, whilst correct fundamental maxims 

 and correct methods of advance would have guaranteed 

 the solution of various problems, and secured the progress 

 of the science." 



This sweeping condemnation of all the work of the 

 previous century savours rather too much of Gratiano's 

 " Sir Oracle," for remember these sentences were written 

 scarcely fifty years after Ingen-Housz wrote his Experi- 

 ments, and considerably less than fifty after the days 

 of De Saussure and Knight, and surely it cannot be 

 said that these men wrote books instead of examining 

 plants or discovered no new facts. Of course, as was 

 only to be anticipated, the Principles contained very 

 many blunders of observation, as well as numerous quite 

 erroneous deductions from facts observed by Schleiden 

 himself. His criticisms also were often not only offensive 

 in their phraseology but ridiculous in their substance. 

 Yet with all its defects there can be no doubt that 



