258 THE PLANT WORLD. 



through this little grove. Each day in the garden one can walk 

 beneath the Cryptomerias and find new pleasure and satisfaction. 



On the whole the botanical garden at Tokyo is not a great 

 institution, but it is one of which any university might well be 

 proud. It answers the purposes of study very well. It is so ar- 

 ranged that the most satisfactory results are obtained with com- 

 paratively little money outlay. For native students of botany it 

 is of the greatest importance since it enables them to become 

 acquainted most readily with their own flora. 



Every student of botany should be a traveler. Every traveler 

 who would appreciate the country which he sees should know 

 something about plants. The easiest way to gain an introduction 

 to Japanese botany is by study in the botanical garden at Tokyo. 

 American botanists especially should know something of the 

 " land of the rising sun " whose plant life can here be so easily 

 studied. 



LICHENS: THEIR ECONOMIC ROLE. 



By Professor Bruce Fink, 

 Miami University. 



Far back in the very distant past some fungi took to a method 

 of life very different from that of the great majority of closely 

 related species. That peculiar digression was an intimate associ- 

 ation with certain algae, green or blue-green. The symbiotic 

 relationship entered into was doubtless at first accidental, but it 

 proved beneficial to fungus or alga or both, and has been perpetu- 

 ated. When the first such association of algae and fungi took 

 place will never be known, but some undoubted fossils of lichens 

 have been found as far back as Tertiary times, — perhaps 2,000,000 

 years ago. Since the time of first association of alga and fungus 

 in a symbiotic relationship, that relationship of the chlorophyllous 

 plants and fungi entering into the symbiotic partnership has be- 

 come more and more intimate as age after age has passed, until 

 now some investigators regard lichens as autonomies or morpho- 



