Jii.Y 1000.] ROTANICAL SOCIKTY OF EDINBURGH 331 



In the course of tlie examination the inflorescence 

 axes have been studied, and the leaves and epidermal 

 appendages. In regard to the latter, if one exclude the 

 pilose papilla' of the petals, the hairs are of two kinds — 

 (a) thickwalled, conical, usually unicellular, with a bulbous 

 base often partly ensheathed by a rosette of epidermal 

 cells ; and (h) multicellular, capitate, glandular hairs, similar 

 to those of the PrimulaceiP. The glandular head is 

 usually of a single cell, but may be bicellular, with 

 the septum vertical. One or both kinds of hairs may 

 occur on the surfaces, margins, and apices of the leaves, 

 on the axes of inflorescence, and on epicalyx and calyx 

 segments. On the torus only the unicellular hairs occur, 

 and these also it is which form the barrier ring over, 

 and internal to, the nectaries. 



In addition to the general anatomy of the flower, the 

 minute structure of the various parts has been studied, 

 as well as the mature achenes, and the seedlings at 

 various stages. 



In the following account of the flower, chiefly those 

 points are dealt with which appear to be of value for 

 purposes of classification. 



The flowers may be solitary, but are frequently grouped 

 into somewhat open inflorescences composed of dichasial 

 cymes arranged on a primary racemosely branched axis. 



In section, the flower shows a shallow concave torus 

 shaped liked the bottom of a bottle, with a solid core. 

 The periphery bears a circle of green segments, usually 

 five in number, forming the epicalyx : each of these 

 segments has been described as composed of the two 

 fused stipules of adjacent sepals — this because the 

 epicalyx segments may bifurcate. Examination of the 

 developing flower, and of the vascular supply of the adult 

 segments, cause me to differ from this com^monly accepted 

 view, and regard the epicalyx segments as integral units 

 as much so as each sepal in fact is. 



Characters of the epicalyx of use for systematic woik 

 are the relative length of the segments ; they may be 

 longer or shorter, narrower or wider than the sepals. 

 Again, their margins may be minutely toothed, each tooth 

 topped by a hair, and occasionally having a watei-gland. 



