The Production of Adventitious Roots and their 
Relation to Bird’s-Eye Formation (Maser- 
Holz) in the Wood of Various Trees. 
By 
A; W. BORTHWIGK, D.Sc; 
ASSISTANT TO THE Proressor oF Botany AND LECTURER ON PLANT 
PuysioLocy, University oF EDINBURGH. 
With Plates VIII.-XI. 
In the spring of 1903 my attention was called by the Regius 
Keeper to the fact that many cherry-laurel shrubs (Prunus 
Laurocerasus, Linn.) in the Royal Botanic Garden, Edinburgh, 
as well as elsewhere, were prone to produce an abundance of 
adventitious roots, and under his direction I began an examina- 
tion of the phenomenon with the object of determining what 
conditions brought about their formation. 
While searching in the Garden for material showing roots in 
Various stages of development I came across three young maple 
trees, each of which had produced numerous adventitious out- 
growths somewhat resembling those on the cherry-laurel, and 
Subsequently the Regius Keeper showed me two young apple 
trees which were literally covered with outgrowths of a similar 
nature. After that I commenced a systematic search through- 
out the Garden in the hope of discovering other examples, with 
the result that similar formations were found on several speci- 
mens of wych-elm, Lawson’s cypress, and Thuja gigantea. 
A few microscopical sections soon confirmed the original 
impression that those adventitious structures were in reality 
roots. They could be traced back as round cylindrical prolonga- 
‘Notes, R.B.G., Edin., No. XVI, 1905.] 
