THE HIGHER CRYPTOGAMIA. 51 



stalk of the ripe bud detaches itself from the wall of the 

 receptacle ; the bud is ejected through the narrow tube of 

 the lageniform receptacle, and becomes free. The escape of 

 the buds is doubtless caused by the pressure which the 

 numerous, rapidly-groVing young buds, necessarily exert 

 upon the mucilaginous contents of their receptacle, which 

 contents are thereby in constant motion towards the opening 

 in its neck. 



It is stated in some books that the bud-receptacles of 

 Blasia are closed when young, and open at the top at a 

 later period (see Nees v. Esenbeck, Naturgesch. d. Europ. 

 Lebermoose, B. 3, s. 395). An incorrect figure of Hed- 

 wig's has probably given rise to this erroneous notion (see 

 ' Theoria generationis/ ed. 2, t. xxx, fig. 9). 



The germination of the German liverworts, irrespective 

 of the very special wonderful development of the spores of 

 Blasia (see the beautiful observations of Gottsche, N. A. A. 

 C. L., vol. xx, p. 1 ; and the supplementary ones of 

 Gronland, ' Ann. Sc. Nat.' ser. iv, t. i, pi. 3) ; exhibits at 

 least three essentially different methods of development. 



Frullania dilatata has the largest spores. They are longish 

 and tetraheclral, with rounded edges and angles ; more 

 rarely spherical. The inner membrane is as clear as glass, 

 and not very delicate ; the outer one is thin, membranous, 

 and of a yellowish-brown colour, beset at regular distances 

 with circular groups of brown protuberances (PI. XI, fig. 

 27). The contents consist of a yellowish, viscous fluid, in 

 which numerous granules are suspended. In the middle 

 point of the spore a roundish ball of opaque matter (a 

 nucleus surrounded by granules) is indistinctly seen. The 

 germination of the spores commences as early as the fifth 

 day after sowing. Numerous very small chlorophyll bodies 

 are formed in the fluid contents. The primary central nucleus 

 disappears, and in its place are found two new ellipsoidal 

 nuclei. From eight to twelve days after sowing, these 

 nuclei appear separated by a delicate line, which is the side- 

 view of a septum, dividing the spore into two cells (PI. XI, 

 figs. 20, 29). One of these cells divides rapidly and con- 

 tinually by alternately inclined septa (PI. XI, figs. 30 34) ; 

 the daughter- cells thus formed divide by radial septa. The 



