ON THE DEVELOPMENT AND STRUCTURE OF MOSSES. 21 



off at an early stage of growth, as in Milium, but sometimes 

 crowning the sporangium till it arrives at maturity, as in many 

 Hypna. If it remains entire at the base, or is only split into 

 several more or less symmetrical lobes, it is called mitriform ; 

 but if the fissure is confined to one side only, it is termed 

 cucullate (hood-shaped) or dimidiate. The base is sometimes 

 fringed, as in Daltonia splachnoides (Plate 3, fig. 4), and some- 

 times has little membranous appendages, as in several Enca- 

 lyptce. These are at first inflected, being derived from the sur- 

 face of a conical appendage to the vaginula within the veil, 

 which ultimately forms an ocrea to it (Plate 22, fig. 1). 



The surface is sometimes even, sometimes granulated, scaly, 

 or spiny, and sometimes grooved or costate. It is either quite 

 naked or clothed with filaments, which are sometimes erect, 

 sometimes dependent. In Polytrichum and Pogonatum they 

 form a striking character, and are so much developed that 

 they entirely conceal the minute veil. The top of the veil is 

 for the most part oblique, and is thicker than the base, and 

 sometimes granulated when the rest of the surface is even. 

 This in a young state was formerly regarded as a real stigma, 

 but it is rather analogous to the elongated fimbriated coat 

 of the ovule in Gnetum, impregnation being effected by imme- 

 diate contact of the spermatozoids with the embryonic cell, 

 if so it may be called, where the result of impregnation is a 

 sporangium and not a plant. 



Occasionally the veil swells towards the base long before 

 the sporangium is large enough to force it out, as in Funaria 

 (Plate 16, fig. 6) and Physcomitrium, in which cases it has a 

 peculiar vesicular appearance. 



The fruitstalk is sometimes curved at the base, within the 

 vaginula, as occasionally in Encalypta and Campylopus. It is 

 often quite even, but not unfrequently the surface is distinctly 



