THE HIGHER CRTJPTOGAMIA. 105 



The protruding portion is separated by a transverse septum 

 from the rest of the cavity of the cell, which is then divided 

 by a longitudinal septum. The cells which are elevated 

 above the margin of the wall are transformed into flat 

 teeth, consisting of a single row of cells, resulting from a 

 division by transverse septa, which is continually repeated 

 in each apical cell (PL XV, fig. \ b ). Repeated division 

 takes place in the interstitial cells by means of longitudinal 

 septa perpendicular to the broader surface ; and by this 

 division, which begins at the base and progresses to the 

 apex with increasing intensity, the teeth, at a later period, 

 increase in breadth. At the same time the circumference 

 of the annular wall of the bud-receptacle increases, through 

 the division of its cells by means of longitudinal septa. 

 At the points of origin of the teeth this latter increase cor- 

 responds with the expansion of the teeth ; underneath it is 

 much less. By this means the form of the edge of the 

 bud-receptacle becomes that of a cup. 



Some time before the appearance of the marginal teeth 

 the formation of the first gemmse commences. Individual 

 cells of the base of the receptacle produce a papilla upon 

 the middle point of their free upper wall (PI. XV, fig. i h ). 

 This papilla is soon separated by a transverse septum 

 from the rest of the cell-cavity. The new semi-oval cell, 

 after previous longitudinal expansion, is divided by a 

 transverse septum (PI. XV, fig. V). The lower one of 

 the cells thus produced is the stalk, the other the mother- 

 cell of the gemma. The latter increases considerably in 

 breadth, and by means of transverse division, which is always 

 repeated twice in the terminal cell, it becomes transformed 

 into a row of four short, wide, and low cells. Each of them 

 divides by a longitudinal septum (PL XV, fig. 2). The 

 three lower pairs of cells thus formed are divided by septa 

 parallel to the last-mentioned septum ; the lower pair once, 

 the two higher pairs twice. The repetitions of the division 

 occur, as is usual in similar cases, always in the outer cells. 

 Each of the two apical cells of the bud, on the other hand, 

 divide by septa having a strong lateral inclination, into an 

 inner and an outer cell, the former having a trapezoidal, 

 and the latter a triangular basal, outline. The former is 



