Ewart — On the Staminal Hairs of Thesium. 285 
Proposed classification of the genus Thesium, 
ACCORDING TO THE STRUCTURE OF THE FLOWER. 
The material examined in the elaboration of the series 
described above, on which is based the foregoing explanation 
of the part played by the staminal hairs, consisted, except in 
the case of five species which have been detailed more fully, 
of dried specimens, which had to be boiled for some minutes 
and then placed in spirit before sections could be cut ; it was 
probably on this account that I was unable to find any 
staminal hairs in them, in which separation between the 
terminal cap and the remaining portion had not been com- 
pleted ; most likely they had been broken off during the 
drying. However, in most cases the constrictions at the free 
ends were clearly marked, especially in those flowers in which 
the hairs were directed downwards. 
The pendent filaments of the perianth, after boiling, swelled 
up until they resembled those of the spirit specimens, and 
probably had undergone very little change during the process 
of drying. When very abundant they appeared to be usually 
white in colour, and to press back the segments of the 
perianth, as shown in Figs. 11 and 13, and, as it were, to keep 
the flower open. 
The order Santalaceae is divided into three sub-orders — 
the Anthoboleae, Osyrideae, and the Thesieae. In the Antho- 
boleae the ovary is superior ; in the Osyrideae it is more or less 
inferior, the perianth is not greatly elongated, and an epigy- 
nous disc is usually present. Comandra was the only genus 
in this sub-order which I examined. The Thesieae, however, 
show an advance on these older types by their lengthened 
perianth, inferior ovary, and the insertion of the stamens high 
up in the perianth-tube. 
The sub-order Thesieae, is defined as possessing a ‘ disc ’ 
whose limits are usually not distinctly defined, and with 2-3 
ovules upon the placenta 1 . It consists of the folio wi ng genera, 
which differ but slightly from each other : — 
1 Engl, and Prantl, Pflanzenfam. (Santa!.). 
