THE HIGHER CRYPTOGAMIA. 109 



same arrangement of the cells as the vigorous normal 

 shoots of the mother-plant ; this may be observed most 

 clearly in Fegatella conica. The mode of ramification of 

 this second form of bud agrees with that of germ-plants ; 

 the fore edge widens considerably, the lateral portions 

 grow more vigorously than the median point, and from the 

 latter a new shoot protrudes, at whose sides the shoots of 

 a new order originate. This process differs materially 

 from the development of the bulbils. There is here the 

 same difference as exists between the development of the 

 germ-plants and the buds of Riccia. 



The leaves of the Marehantiese are delicate lamellae of cellu- 

 lar tissue, closely pressed to the under side of the flat stem. 

 In an advanced state they sometimes exhibit at the base a 

 double layer of cells containing a small quantity of chloro- 

 phyll, the remainder consisting of a single layer of hyaline 

 cells. They develope themselves in a backward direction, 

 towards the place where three shoots unite to form one shoot, 

 and are situated on the under side of the shoot, in two rows 

 parallel to its longitudinal axis, arranged according to the 

 fraction J. The first rudiments of the leaf are formed as 

 follows : one of the cells of the under side of the stem 

 protrudes outwardly, and the protuberance becomes divided 

 from the original cell-cavity by a transverse septum (PL 

 XVI, fig. 15). At this time the stem is but little developed 

 in breadth, and is almost semicircular in a transverse 

 section. The rudiment of the leaf increases in length by 

 repeated transverse division of its apical cell. The cells 

 of the second degree are divided by longitudinal septa 

 (PI. XVI, figs. 15, 16). In Fegatella conica this division, 

 even in the youngest stage of the leaf, extends as far as the 

 apical cell ; the leaf, when only four cells in height, appears 

 to consist of a short, double row of flat cells (PI. XVI, 

 fig. 11). The three pairs of interstitial cells divide by 

 septa parallel to the margin, and the two apical cells by 

 septa inclined somewhat laterally. The two inner ones of 

 the four cells which at this period constitute the fore 

 edge of the young leaf are now divided by transverse 

 septa, and the four cells thus formed by longitudinal septa 

 (PI. XVI, fig. 12). The outline of the leaf then becomes 



