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DAS MOOSBILD OF DR. ERNST HAMPE. 

 By Robert Braithwaite, M.D., F.L.S., etc. 



II. 



In reviewing Dr. Hampe's arrangement of mosses given in Vol. 

 i., p. 10, we have first to consider the value of the two sections 

 under which the families are grouped ; and these, it will be seen 

 depend on a single character — the condition of the calyptra. The 

 large saccate hood in the three families included in Saccomitria is 

 torn irregularly by extension of the fruit (and, indeed, it is the 

 degree of expansion in the capsule which determines the form of 

 the calyptra in all mosses), but w T e may question whether this cir- 

 cumstance is deserving of the importance attributed to it, since in 

 all other points they have nothing in common, and we incline to 

 follow the view of preceding authors that Sphagnum in its leaf- 

 structure, arrangement of branches, and internal anatomy of stem, 

 differs so far from all other mosses as to be entitled to represent a 

 subclass. Andrecea, notwithstanding its affinity in leaf-structure to 

 Grimnilacea?, cannot be allied with them, as some authors have 

 done, but may conveniently remain as the section Schistocarpi. 

 Archidium agreeds too closely with Pleuridium in most of its cha- 

 racters to permit of its being separated far from that genus, and 

 both of them appear to have their most natural position as the 

 lowest members of a series comprising Seligeria, Ditrichum and its 

 allies, Dicranella, &c, with Dicranum as its highest form. 



In the second section we have a return to some of the old sub- 

 divisions characterised by the position of the fruit, and the Cleisto- 

 carpous group is maintained, although the learned author was one 

 of the first who broke up the Phascoid mosses, and distributed 

 them among "families containing more highly developed species ; as 

 he also was to indicate the importance of the areolation in all 

 mosses, by which in recent years we have acquired such additional 

 facilities in the discrimination of species. 



Pottiaceaj and Blindiacere are adopted instead of Trichostomacea3 

 and Dicranaceas, because, says the author, it would be barbarous to 

 apply such terms to families which include mosses having no peris- 

 tome. We do not see the force of this reasoning, but would regard 

 ;i moss to be Dicranaceous which agreed with the genus Dicranum 

 in its most important characters, and not necessarily that it should 

 have the bic rural teeth of Dicranum; besides, the great genus 

 Dicranum) being the best developed in the group, must stand as 

 the type ; and the same applies to genera, for we should have to 

 separate species without a peristome, if the generic name imply 

 that one be present, e. g., Zygodon viridissimus. 



