West. — A Contribution to the Study of the Marattiaceae. 397 
Bower concluded ( 7 , p. 315) that his own observations on roots of 
Marattia fraxinea and of Angiopteris evecta bore out Schwendener’s con- 
clusions rather than those of Russow. Farmer ( 28 , p. 268) stated with 
reference to the root of the embryonic plant of Angiopteris evecta , that ‘ the 
apical cell, which is at no time very clear, is subsequently replaced in most 
cases by a group of initials and suggested that some connexion may exist 
between the robust condition of the root and the structure of its apex. 
In a long paper devoted to the subject of apical growth in roots, 
Koch ( 41 ) put forward the view that no persistent apical cell is present in 
roots of Angiopteris , the function of the apical cell being temporarily 
assumed by one of four particularly large cells that are found at the apex of 
the roots of this genus. 
Text-fig. 25. Danaea alata , Sm. A and P,. Apex of small roots in transverse and 
longitudinal section respectively, showing the single initial cell, x 200. 
Accordingto Jonkman ( 39 , p. 224), the apical meristem of the primary 
root of Marattia and of Angiopteris consists of £ un groupe de quatre 
cellules environs’ ( 1 . c., PI. VI, Figs. 15 and 16). 
Brebner ( 10 , p. 119) concluded that a single initial cell was present 
at the apex of the primary root of Danaea simplicifolia ) but that the 
adventitious roots possessed a group (sometimes four) of equivalent initials. 
The most important contribution to this subject is the recent 
comparative work of Campbell (20 and 21 ), who finds a single initial 
cell at the apex of the primary root of Angiopteris , Danaea , K aidfussia> 
Marattia , and Macroglossum ; this botanist adds, however, that in the later 
roots of Danaea , Marattia , and Macroglossum , the single apical cell is 
replaced by a group of apparently equivalent initial cells which are wedge- 
shaped in longitudinal section. 
The present writer, working on Danaea alata , Danaea nodosa , Angio- 
pteris evecta , Kaulfussia aesculifolia, and Marattia Cooper i, has obtained 
results on the whole very similar to those of Campbell. A single apical cell 
of moderately large dimensions and of variable shape is found at the apex 
of the primary and earliest adventitious roots of the above-named genera and 
E e 2 
