THE HIGHER CRYPTOGAMIA. 265 



ledonous plants, and of the forked branches of ferns. I 

 should not adopt the definition given by Mettenius of 

 lateral and adventitious buds. I should call those buds 

 lateral buds, which originate from the naked apex of the 

 stem above the insertion of the youngest leaf, and are thus 

 formed by bifurcation of the end of the stem, whilst 

 owing to their inferiority of development they are pushed 

 aside by the other division of the forked end of the stem. 

 I should call those buds adventitious which make their 

 appearance underneath the insertion of the youngest appen- 

 dicular organ, whether on the outer surface or in the interior 

 of the tissue. The term Dichotomy might then be applied 

 to the cases of equal development of the two ends of 

 the fork of the stem. These definitions leave the doctrine 

 of ramification as established by Schimper untouched. 

 The fact, that in phaenogams that branch of the end of the 

 stems which is situated in the axil of the next lower leaf 

 is usually less vigorously developed than the other one, 

 justifies the assumption, that the cases in which the former 

 is more vigorously developed than the latter must be 

 looked upon as special instances of ramification. If a 

 comparison be made between the adventitious buds of 

 Asjridium fillv-mas (which are of frequent occurrence), and 

 the early conditions of the bifurcations of the apex of the 

 stem of the same species (which are of rare occurrence), 

 or between the bifurcations of the apex of the stem of 

 Jsplenium fllix-femina (which are of frequent occurrence), 

 and the adventitious buds at the base of the stipes of 

 the latter plant (w r hichare of very rare occurrence), it will be 

 self-evident than in these instances the two things are quite 

 as distinct as (for example) the bifurcations of the end of the 

 stem of Metzgeria furcata , and the adventitious shoots 

 which are developed from the marginal cells of the flat 

 stem of the latter plant. 



Upon examining the bifurcations of Asplenium jilix- 

 femina whilst in a very early stage of development, after 

 having removed all the older fronds and scales, I found that 

 the two ends of the axis, when viewed from above, presented 

 the appearance of conical protuberances of equal size, 

 each surrounded by the rudiments of only three fronds. 



