326 Szabo.—The Development of the Flower of the Dipsacaceae. 
ovary, forming three whorls (calyx, corolla, stamens). The zone of the 
sympetalous corolla in the genera Knautia , Dipsacus , Succisa , Succisella , 
and Cephalaria is four-membered. The four episepalous diagonal stamens 
with their filaments grow on the top of the corolla. The calyx is situated 
on the spindle-shaped ovary and has a various number of members: in the 
tetramerous genera ordinarily four, in the pentamerous genera five. The 
inferior cupular ovary has only one cavity with a single anatropous pendent 
ovule. The situation of the latter is epitropous introrse. The stigma is 
double in the groups Knautiae and Scabiosae (van Tieghem’s ‘ Knautiees 
et Scabiosees ’), but it is simple in Dipsacus and Cephalaria. 
To complete my former investigations of the flower of the Knautiae, 
which have two stigmas and no bract, I chose the flower of Cephalaria as 
the subject of my present study. This flower is completely tetramerous, 
with a single stigma and bract. The flower with a single stigma shows the 
greatest reduction, and the presence of a bract is necessary for any conclu¬ 
sions possible as to orientation. 
II. The Development of the Flower. 
All authors, since Payer’s investigations (6), agree that the succession 
of the development of the different flower-parts is uniform throughout the 
family. The four protuberances of the involucel appear first. According to 
Gjurasin ( 4 ) the two median protuberances appear first, and the two trans¬ 
verse ones later (PL VII, Figs, i, 2). The flower-protuberance is still 
closely covered by the bract. Alternately with the four protuberances of 
the involucel arise the four protuberances of the calyx (PI. VII, Fig. 3), and 
these are alternate with those of the corolla, which develop still later. 
During further growth, the development of the zone of the gamosepalous 
calyx (k) is slower than that of the gamopetalous corolla and of the 
involucel. The development of the corolla (PI. VII, Fig. 5) is the most rapid. 
Alternating with the median-transverse protuberances of the latter, the pro- 
tuberances of the stamens appear. The common basal part of the staminal 
and corolla whorls elongates to become the tube of the corolla (see Text- 
fig. 2), therefore the stamens and the tube of the corolla have grown together 
at their lower part. On PL VII, Fig. 6, there is shown the stage in which 
the four median-transverse protuberances of the involucel have become 
strong, and, what is more, there appears between them a protuberance 
diagonally situated. The teeth of the calyx situated diagonally are the 
strongest. Among the four protuberances of the corolla, the one in the 
front is a little larger; its situation is median, near the bract (b). The 
figures of PL VII show nearly the same gradations as Payer’s Figs. 1, 2 
(relating to Dipsacus). It is a pity, however, that in Payer’s figures no 
