7) 
of opinion is to science what the governor is to the engine, it in- 
Sures a more steady progress by urging more thorough study and 
greater care and consistency in formulating conclusions. It is, 
however, a fact which cannot be denied that (with a few excep- 
tions) the most vehement objectors to Reinke’s theory are those 
who have little scientific perspective and who have done little or no 
Scientific work in lichenology. Among the more scientific class 
of botanists the principal cause of the difference of opinion lies 
in the difference of the point of view. The Schwendenerians are 
essentially morphologists (histologists) of the older school who 
consider structure and not function of prime importance. The 
followers of Reinke are the product of the modern school of bio- 
logical investigation which teaches that the morpho-physiological 
method is the true one. That is, it should be the investigator's 
Purpose to give a proper physiological interpretation to the mor- 
Phological conformation. Peculiarly enough Schwendener is quite 
universally recognized as the founder of this school. It should 
also be borne in mind that at the present time Schwendener raises 
NO serious objection to Reinke’s views. 
Until recent years the pure systematists held full sway. Mor- 
Phological studies were resorted to simply as an aid to classifica- 
tion; hence those structures which proved most useful in forming 
or perfecting a system received first attention. In the various 
Systems of fungi the characters of the spore-bearing tissue was 
found most useful, On comparing the apothecia of lichens with 
the reproductive organs of fungi, certain morphological simi- 
larities were noted and at once the conclusion was reached that 
lichens must be fungi. No efforts were made to demonstrate 
whether or not the spores of lichens were functionally the same 
as those of the fungi. The study of the thallus was neglected be- 
Cause it was not clear what practical use could be made of it in 
classifying lichens as fungi. Schwendener himself, as well as many 
investigators before and after him, made careful morphological 
investigations of the various lichen-thalli. Schwendener indeed 
demonstrated that the gonidia in the majority of lichens were true 
algae, but he did not give a true explanation of the relationship 
existing between the fungus and the enclosed algae (gonidia). 
Reasoning from the standpoint of morphology he concluded that 
