306 The Botanical Gazette. [October, 
estan, the most of the Mongolian empire, and Thibet to the 
north slopes of the Himalayas, our knowledge of the hepatic 
flora is almost an absolute blank. ; 
For our knowledge of the hepatic flora of boreal America 
we are indebted largely to the collections of two men, John 
Macoun, who has collected hepatics since 1866 from Nova 
Scotia to Little Slave Lake and the confines of Alaska, and 
Rev. Arthur E. Waghorne, who has collected in recent years 
in Newfoundland and Labrador. From these two collectors 
alone we have examined over a thousand packets of hepatics 
during the past three years. In addition we have the results 
of the labors of Mr. Pearson! on Macoun’s earlier collections, 
and the still earlier collections of Drummond, which were 
worked up by Taylor whose collection at Cambridge furnishes 
considerable material bearing on the northern species. The 
Greenland flora has been summarized by the Danish botan- 
ists’, and several collectors (Krause brothers, J. M. acoun, 
Miss Cooley, and others) have taken scattering species i 
Alaska. The bryology of that region, however, demands 
much more thorough exploration than has hitherto been 
given it. : 
The difficulties arising in the systematic study of these 
northern collections are fourfold:— ; 
The similarity of the American to the European flora, 
rendering necessary a thorough familiarity with all the Buro- 
pean species, varieties and forms. : b 
. The undue refinement of specific distinctions made : 
recent European hepaticologists especially in the genet 
Scapania, Cephalozia, Marsupella, Nardia and Jungermant 
3. The confusion introduced by periodic upheavals 0 
nomenclature, notably by Lindberg among the Scandinavia} 
species, which very largely interlace with those of pas 
4. Absence of many types and inaccessibility of most = 
are in existence; combined with this are the conflicting ae 
ions of European authorities regarding the autonomy rs : any 
tity of many species, and the misleading character 0 m 
European exsiccatae. a ae 
In spite of these difficulties, we are gradually apna 
out of chaos, and hope in time to have the American 
satisfactorily co-ordinated with the European. 
Lect ie 
1List of Canadian Hepaticze, TBoQ; ee i 7-42 
( sane Hepatic in Meddelelser om Gronland, Tredie Hefte, pp. 4° 
1887). 
