460 



tuated indifferently near tlie base or in the axil of a leaf, so that they cannot be consi- 

 dered stipules ; but their most usual position is midway letween two consecutive leaves. 



Accessory leaves of Hypnum jilicinum. 



a — c. Accessory leaves standing singly. d. Accessory leaf and radicles, e, f. Accessory leaves occurring 



in pairs. g Leaf of a branch bud. All the figures are magnified. 



My first impression was that they were branch-buds ; but the true branch-buds, which 

 exist copiously on elongations of the stems, are first displayed as little biilbs bursting 

 forth from the stem, and are composed of closely packed and very minute leaves, of 

 the shape represented at fig. g. Afterwards, remarking that the folia accessoria were 

 confined to the upper part of the stem, while the lower part was profusely clothed with 

 radicles. I thought it barely possible that the former might pass into the latter ; but 

 after a very careful scrutiny I detected several instances of the two organs occurring 

 intermixed, and each preserving its characters unaltered ; thus, the radicles, in their 

 most rudimentary state, were jointed cylinders of a deep brownish-purple hue ; while 

 the accompanying folia accessoria were pale green, cellular, foliaceous expansions : an 

 instance of their conjunction is figured at d. I may add that the folia accessoria are 

 more abundant on the upper, the radicles on the under part of the stem. These pecu- 

 liar appendages I believe have been hitherto unnoticed, although they certainly exist 

 in every state of Hypnum filicinum with which I am acquainted ; it is, however, sin- 

 gular that they should be absent from the very nearly allied species H. commutatum, 

 at least my specimens do not show them. It is by no means improbable that other 

 species of Hypnum may possess folia accessoria, which, from their minuteness, have 

 been overlooked by previous observers ; and perhaps this brief account of what I have 

 myself notited, may induce some of your correspondents, who have a love for musco- 



