251 HOFMEISTER, ON 



cell turns its own edges towards them. These facts are 

 directly contrary to what occurs in Pteris aquilifia, but on 

 the other hand they agree with what takes place in the 

 Polypodieae. 



Marattia Cicutafolia* The flat terminal bud of this 

 fern exhibits, when viewed from above, a three-sided apical 

 cell as in Jspidiuvi filix-mas. Longitudinal sections show 

 a very oblique arrangement of the side walls of the apical 

 cell and of the neighbouring cells. The rudiments of the 

 young fronds surround the flat conical end of the stem in 

 a spiral. The latest formed have the appearance of sharply 

 conical protuberances of cellular tissue flattened in front, 

 hardly distinguishable from the first rudiments of the fronds 

 of the larger Polypodiaceae. 



In consequence of its increased longitudinal growth the 

 top of the young frond bends over in front. During this 

 process the stipula makes its appearance, in the first in- 

 stance at the fore surface of the young frond, in the shape 

 of a transverse protuberance (PL XXXIII, fig. 11). Shortly 

 afterwards a membranous cellular mass grows in a forward 

 direction out of each of the lateral margins of the rudiments 

 of the frond. Those surfaces of the two cellular masses 

 which are turned towards the protuberance of the fore-side, 

 amalgamate with the side margins of the latter (PI. 

 XXXIII, figs. 11, 12). The fore margins of the two 

 lateral lobes of the stipula remain free. In consequence of 

 their rapid further development they almost entirely en- 

 velope the younger portions of the stem-bud. In the 

 mean time the upper margins of the two lateral portions of 

 the stipula grow rapidly and vigorously upwards and back- 



* De Vriese and Hartings Monograph of the Marattiaceae (Leyde et Dussel- 

 dorf, 1S53, pp. 49 and 51) contains statements as to the development of the 

 fronds of the Marattiaceae, which, if correct, show that the process is very 

 peculiar. It is there said, " The formation of each frond is preceded by that 

 of its Perula. ... It covers even the younger frouds partially. . . . 

 The cellular protuberance, in the form of which the younger frond makes its 

 appearance laterally near the terminal bud, consists in Angiopteris originally of 

 cells of equal size, and of equal capacity for multiplication. The outer cells 

 grow and multiply more rapidly, in consequence of which they separate from 

 the inner ones. The former constitutes the membranous portion of the Perula, 

 the latter that of the fronds." My observations on Marattia cicuttrfolia, from 

 which in this respect Angiopteris certainly does not differ, lead to entirely 

 different conclusions. 



