47(5 A. HESSELBO 



Hagen, Bryhn, Ryan, Arnell, Limpricht and other authors, or 

 might with as great justice be described as new species. But without 

 comparison with original specimens, and only according to the descriptions, 

 it is impossible to form any opinion of the value of these species, which 

 have very often been collected only in small quantity, and from a single 

 locality, and which will therefore in many cases prove to be maintainable 

 only so long as there does not exist more than the one specimen. It 

 is very probable that it will not even be possible to maintain as varieties 

 a great many of these forms which have been given specific rank, the 

 characters used for separating the species being so variable that, on 

 having abundant material for investigation, it is impossible to draw any 

 boundary line between the forms. Here, only thorough investigations 

 made at the habitat will be able to throw some light on the influence 

 of the external conditions on the specific characters. 



The height of the tufts and the length of the stems vary according 

 to the degree of dampness, so that plants from dry and exposed habitats 

 are low in growth with close-set leaves, and from damp localities, as a 

 rule, higher, with elongated stems and more distant leaves. Also in 

 places, slightly illuminated, for instance among grass and Car&r-t lifts, 

 do the plants become higher with elongated stems. The leaves in Brynm 

 inclinatiim, in contradistinction to those in several other species of the 

 same group, are stated to be not decurrent. This feature appears, how- 

 ever, to varv considerablv, and to be closelv connected with the habit 



* - ' *j 



of the plant, forms with short stems having close-set, not decurrent 

 leaves, while the leaves on elongated stems are, as a rule, more or less 

 decurrent. In such forms the uppermost close-set leaves have almost 

 always a rounded, not decurrent base, while the leaves further down 

 on the stem become more strongly decurrent the further they occur 

 apart from one another. The form of the cells of the basal angles of 

 the leaf also vary greatly according to the position of the leaf on the 

 stem. The not decurrent leaves have a rounded base with quadrate, 

 somewhat widened and thin-walled cells, but as the leaves downwards 

 become more and more decurrent, the cell-form becomes elongate rect- 

 angular. The leaf-form varies from narrow-lanceolate to almost ovate, 

 with a shorter or longer point. The lower leaves are usually shorter 

 and broader, and the nerve vanishes just below the apex. The leaf- 

 margin is revolute to the apex, more rarely it is plane in the upper part. 

 The form of the leaf-cells is partly dependent on the leaf-form, long, 

 narrow leaves having elongated cells, while broad, short leaves have 

 broader cells, and even in leaves of the same plant the cell-form may 

 vary considerably. The cell-walls vary somewhat in thickness. Xero- 

 philous forms have often thick cell- walls, while bog- forms with large, 

 broad leaves have thin-walled cells. The capsule varies in form from 

 obovate to elongate-ovate. The neck of the capsule is usually straight, 

 more rarely slightly curved. 



The peristome teeth vary in colour from pale yellow to brownish 

 yellow, being very strongly coloured where inserted. The "insertion" 

 may be very differently developed, all transitions are met with, from a 

 slightly indicated yellowish-brown or orange ring at the base of the 

 peristome teeth to a highly developed compact thickening (fundus) 



