On Polystely in the Genus Primula 1 . 
BY 
D. T. GWYNNE-VAUGHAN, M.A. 
Assistant at the University , Glasgow. 
With Plate XIV. 
S OME time ago the anomalous variations in structure 
which are found in the stems of the different species 
of the genus Primula attracted the attention of the French 
botanist, Van Tieghem, and they received an admirable 
elucidation at his hands. He showed that while some of the 
species are monostelic, others, on the other hand, exhibit 
a polystelic arrangement of their vascular tissue. However, 
being chiefly intent upon distinguishing between the various 
types of structure exhibited, and upon arranging the species 
according to these types, Van Tieghem did not pay much 
attention to the remarkable variations in structure which may 
occur within a single species, even in the different regions 
of one and the same plant, although these facts had already 
been observed and utilized for the purpose of classification 
1 Van Tieghem, relying chiefly upon anatomical characters, has divided the 
genus Primula , L. into two separate genera, Primula, Toum. and Auricula , 
Toum. This separation agrees closely with that based upon the external 
characters which was established by Tournefort himself about 1700. However, 
it seems best to retain the customary nomenclature. 
[Annals of Botany, Vol. XI. No. XLII. June, 1897.] 
