SPECIAL MORPHOLOGY : MOSSES. 175 



and elongated cells (nerves) proceeding from the base, which some- 

 times stop at the middle of the leaf, and sometimes run along its 

 whole length ; in some, as in Mnium punctatum, we also find two 

 marginal nerves. The leaves are simple, dentated or ciliated, 

 generally scattered (spirally ?) round the stem, sometimes apparently 

 two-ranked, the stem with the leaves looking as if pressed flat (as 

 in Neckera crispa, Hypnum undulatum, &c.). In some few Mosses 

 the leaves actually do occur in two lines, and then differ very much 

 from each other in their structure, as in Fissidens. Here the face 

 of the leaf is folded together, and embraces the stem with the next 

 leaf; above, however, it is continued in a simple, laterally flattened, 

 uniform lamella (similar to the leaves of the Iris). In many 

 Mosses the curved leaves are all bent at the point towards one side 

 (folia secunda), as, for instance, in Hypnum cupressinum, lycopo- 

 dioides, scorpioides, &c. On the first appearance of the stem, it 

 exhibits, especially near the leaves, more or less numerous, longer 

 or shorter filaments of cylindrical cells (adhering fibres, rhizince), 

 which have been termed roots or root-fibres when they appear 

 below, and sap-filaments (parapliyses) when they occur above, espe- 

 cially between the organs of propagation. 



Our knowledge of the course of the development of Mosses, and of the 

 morphological laws by which it is regulated, are still very defective ; for 

 instance, we are wholly unacquainted with the history of the develop- 

 ment of the leaf, and consequently of the importance of its relation to the 

 stem. We have as yet nothing more exact regarding the germination 

 than what the observations of Hedwig* have given us, although there has 

 been no lack of fantastic specious theories. When I find a description 

 of moss germination beginning thus " Soon after the escape of the seed 

 there unfold themselves, as it appears from the solution of several decaying 

 germ-granules," &c. I lose all further desire to continue the perusal. 

 Here we may see at once that the author cared less to give a certain and 

 clear exposition of a strictly scientific observation, than to expatiate in 

 an assumed ingenious manner upon incomplete and superficial views. A 

 fundamental repetition of these investigations is earnestly to be desired ; 

 and until this has been made, that is, until the morphological relation 

 existing between leaf and stem has been clearly ascertained from the 

 history of development, nothing definite can be said concerning the mor- 

 phology of Mosses. A short notice of the mere facts is given in the 

 paragraph. The proembryo has been already described as Conferva 

 castanea Dillw, and as Catoptridium smaragdinum, in Schistostcga 

 osmundacea. According to more recent views, the Moss has been 

 regarded as formed of Confervo3 grown together, under the impression 

 that such a confusion of ideas would make the matter more compre- 

 hensible. 



Thus much is at any rate apparent from the history of germina- 

 tion, that we cannot speak here of a root as morphologically opposed 



* Hedwig, Fundamenta Hist. Nat. Muse. Frond, Leipzig, 1782.; Theoria Genera- 

 tionis et Fructificationis Plant. Crypt., Leipzig, 1798. I have unfortunately not 

 become acquainted with the very recent work of Bruch and Schimper, and consequently 

 I do not know whether it contains anything more. 



