286 BOTANICAL GAZETTE 
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development of the apothecium and thallus are suggested, with some reference 
to the spores and algze. In view of the earlier statement that it is impos 
ble “to study out the ancestral fungal types at present,” the use of those 
fungal types as a basis of classification must be difficult. As generic char 
acters the spore characters are given as of primary importance; then the 
development of the thallus, the apothecium, the exciple, the color of the 
apothecial disk, the alga, and the color of the thallus. A number of genera 
are based upon algal differences. As to specific characters our author sy _ 
‘‘in general it may be stated that in the establishment of species all know 
characters must be considered more or less.” Chemical reaction 1s a 
sidered of no importance in distinguishing species. : 
‘One turns with considerable interest to Dr. Schneider's application of ” : 
principles of classification, and it is inevitable that one should compare bis 
work with the classic work of Professor Tuckerman in the same - 
Thirty-four years élapsed between the publication of Professor Tuckermas* 
Synopsis of the Lichens of New England, the other northern states at 
British America, and his publication of his Synopsis of the North A i 
or less exclusively val 
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i 
mature judgment. His Syofsis covers the whole of 
Susy 7: ext-book, eaten United States. We find seven] 
genera in Professor Tuckerman’s Synopsis, while Dr. Schneider ge ‘. 
seventy-seven genera. If we deduct the thirteen genera see in te 
Professor Tuckerman of which no species are recorded as yeni . 
region covered by Dr. Schneider, and the eleven genera por Schneider - 
Professor Tuckerman as occurring in that region but of which Dr. -_ 4 
makes no mention, we can better appreciate how the Tuckerman 
have been divided up. : art 
But what of ar weniyied new genera thus established ? aaah 
recognized by Professor Tuckerman as sections under hi ae a vey 
distinct genera by other lichenologists, but many are establ ider says * 
slight basis, as for instance Ma//otium, of which Dr. Schneider $47" 
essential character which distinguishes this genus from se hich exe 
presence of numerous long, comparatively rigid, gray a e great 
in clusters from the lower surface of the thallus.” be ia 
bility in the development of rhizoids is considered, one !S a than Profes** 
made the basis of a genus. Is this so much more ie ed a 
Tuckerman’s work, of which our author says “ie ae ansatisfacr 
genera of lichens and their relationships, which is, hower aa 
r conception of ae 
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