114 HORSETAILS. [BOOK i. 



also a division of the reproductive mass before it escapes 

 from the plant, so that the numerous sporules of the Moss 

 furnish no argument against the hypothesis just advanced. 

 As a further argument in favour of the idea of the capsule of 

 the Moss being the product of a mixed endochrome, it is 

 stated by Bruch and Schimper that the capsule itself is not 

 developed unless the two so-called sexes of the species are in 

 proximity." (Annals of Natural History, i. 165, n. s.) 



For observations on the morphology of Urn Mosses the 

 reader is referred to the Vegetable Kingdom, p. 65. 



In SPLIT MOSSES (Andraeacese) the sporangium is not an 

 urn-like case, but splits into four valves, cohering by the 

 operculum and base. 



In HORSETAILS (Equisetacea?) the stem is hollow, jointed, 

 and bears a toothed sheath at each joint. The cylinder of the 

 stem is pierced by longitudinal fistulae, which alternate with 

 furrows on the outside of the stem ; there is also a bundle of 

 ringed ducts connected with the fistula. 



The organs of reproduction are arranged in a cone, con- 

 sisting of scales bearing on their lower surface an assemblage 

 of cases, called sporangia, thecae, folliculi, or involucra, which 

 dehisce longitudinally inwards. In these sporangia are con- 

 tained two sorts of granules ; the one very minute and lying 

 irregularly among a larger kind, wrapped in two filaments, 

 fixed by their middle, rolled spirally, having either extremity 

 thickened, and uncoiling with elasticity. By Hedwig the 

 apex of the larger granules was supposed to be a stigma, and 

 the thickened ends of the filament anthers, the small granules 

 being the pollen. It is certain that the larger granules, round 

 which the elastic filaments are coiled, are the reproductive 

 particles. Mr. Griffith states that the club-shaped bodies 

 which Hedwig referred to stamens are in reality analogous 

 to elaters, and are developed in or on a loose membranous 

 coat, and later than the central body, spore, or seed. This 

 statement has been confirmed by Henderson and Mohl. 



SCALE MOSSES (Jungermanniacese) and LIVERWORTS (Mar- 



