52 Mr. W. Mitten's Remarks on Mosses, 



Smith, that the author's attention was first arrested by the fact 

 that all the Cleistocarpous Mosses might be distributed among 

 the Stegocarpous genera ; since which the subject has been neg- 

 lected ; and he now publishes his ideas from seeing in the most 

 recent works on bryology the continued adhesion to the old plan 

 of keeping up a class of Cleistocarpous genera and species. 



In all arrangements of plants, Mosses, Musci, and Liverworts, 

 Hepaticce, are placed after Equiseta, Lycopodia, and Ferns, as 

 though these tribes were possessed of a higher degree of deve- 

 lopment ; and even in the last systematic work on Mosses, by 

 M. C. Miiller, the definition of the order commences with 

 " Planta? Agamse," a term altogether inapplicable to Musci and 

 Hepaticce, however well it may agree with the tribes above men- 

 tioned, which, so far as seems known, are truly agamous. 



The Musci may be defined as follows : — 



Plants with stems bearing horizontal leaves which are mostly 

 composed of one layer of cells and furnished with thickened 

 nerves. Inflorescence surrounded by proper involucral leaves. 

 Male flowers composed of anthers, antheridia : female of pistils, 

 archegonia, which, as well as the antheridia, are mixed with 

 slender threads, paraphyses. Fruit an unilocular capsule burst- 

 ing at the sides or operculate, surmounted by a calyptra. 



From this definition it is apparent that the Musci are neither 

 agamous nor cryptogamous, but are the highest order of Aco- 

 tyledons, forming the next link to Monocotyledons, and, with 

 Hepaticas, are entitled to take precedence of the Filices, Lyco- 

 podia and Equiseta, in which inflorescence is unknown. On one 

 side the Musci, with their horizontal nerved leaves and the pre- 

 sence of stomata in their capsules, approach to Monocotyledons ; 

 on the other side the Hepaticse, which, with their nerveless semi- 

 vertical or vertical leaves, and the form of their perianths, espe- 

 cially in Jungermannia, Plagiochila and Radula, resembling very 

 closely the involucra of Hymenophyllum and Trichomanes, come 

 near to the Filices. 



The inflorescence of Mosses is dioicous, monoicous, or her- 

 maphrodite. In the growth of the species that are usually 

 termed acrocarpous, the first flower produced appears to be 

 always male ; and it is upon an innovation from beneath, or 

 rarely through this, that the female flower and fruit are borne. In 

 some species the antheridia are found in the axils of the comal 

 without proper involucral leaves ; not springing out as a 

 secondary growth, but appearing to be left there by the elonga- 

 tion of the axis, which has passed as it were through the first and 

 male flower to form the female, as seen in Bryum nutans. In 

 Polytrichum undulatum after the production of a male flower the 



