THE HIGHER CRYPTOGAMIA. 247 



Adventitious buds are very rare in Asplenium filicc- 

 femhia ; it would seem that they never occur when the 

 plant is growing naturally. However at the base of the 

 stipes of a frond which had been torn off and kept for some 

 time in a closed bottle in moist air, I saw adventitious buds 

 produced underneath the place of attachment of the roots 

 (PL XXXIII, fig. 1). On the other hand the forking of 

 the apex of the stem by division of the frond-less terminal 

 bud is in this fern quite a normal process ; it is the usual 

 asexual mode of multiplication of the plant which it would 

 seem occurs at tolerably regular intervals. The observer 

 will seldom fail to find the bifurcation of the stem in old 

 plants ; specimens often occur with from four to nine 

 heads. 



In Struthiopteris germanica * the formation of numerous 

 adventitious shoots is added to the other peculiarities already 

 mentioned.! As in Aspidium spinulosum, they originate 

 on the outside, at the base of the stipes, close above its in- 

 sertion into the stem. The first commencement of their 

 formation occurs unusually early, long before that of the 

 blade of the frond. In their first development they are 

 directed obliquely downwards (PI. XXXIII, figs. 7, 8). 



The copious production of adventitious buds on all parts, 

 even on the ramification of the blade of the frond, is very 

 remarkable in Asplenium Bellangeri. The mode of develop- 

 ment is essentially the same as in Aspidium filix-mas. 

 Here also the new shoots do not originate in the interior of 

 the tissue of that portion of the plant which produces them, 

 but outside, on its outer surface. 



It is well known that the species of Nephrolepis send 

 forth long thin runners, whose ends, in Nephrolepis undu- 

 lata and N. tuberosa, swell into knobs, f The stolons 

 originate from adventitious buds, which are produced 

 apparently on the stem, at that part of the base of the 

 frond which amalgamates with, and forms a bark to the 

 stem (PI. XXXIV, fig. 3). The runners are one third of a 

 line thick, and sparingly clothed with pale yellow scales ; 



* On the distribution of the vascular bundles, see Schacht, ' Pflanzenzelle,' 

 PI. xv, fig. 36. 



f See Braun, ' Verjiingung,' p\ 115. 

 + Kunze, <Bot. Zeit.,' 1849, p. 881. 



