FLORAL ANATOMY OF SOME COMPOSITÆ. 523 
original function of the style has been lost and a secondary function acquired, 
which requires, if anything, more rigidity in the style than does the original 
function *. А similar case is that of Arctotis aspera, previously reported 
on (11) in connection with an irritable pollen-presentation mechanism. 
Here the comparatively thick style remains upright and undivided during 
the male stage, and an examination of hand-sections shows the presence of 
four vascular bundles in the lower half of the thick part of the style. The 
two lateral bundles end near the separation of the style branches. 
The lower distributive centre in these male florets of 7. Farfara (fig. 4, 
diag. 12) is similar to that in the ray florets, but the ring is not so well 
marked and only an abbreviated vestige of the ovule remains (fig. 4, 
diag. 13). In the upper distributive centre (fig. 4, diag. 15), which is 
also similar, the two lateral bundles supply the two lateral stylar bundles ; 
the two anterior bundles supply the anterior stylar bundle; and the posterior 
bundle supplies the posterior stylar bundle. The cavity of the ovary persists, 
as do the strands of the stylar canal (fig. 4, diags. 18 & 14). The short 
pappus is a single row of laciniæ, not a double row as in the ray florets 
(fig. 4, diags. 6 & 16). The five lobes of the corolla are longer than in 
Senecio vulgaris (fig. 2, diag. 8 & fig. 4, diag. 19), and the tips of the lobes 
show the same fusion of the divided strands (fig. 1 & fig. 4, diag. 20) as in 
the latter species. The four stylar bundles end near the base of the aborted 
stigmatie region. 
It will be seen from the foregoing account that, while the anatomy of the 
ray florets in Tussilago Farfara differs considerably from that of the ray 
florets of Calendula officinalis, it shows no similarity to that of the ligulate 
type which is so constant a feature of the Cichorieæ. The constaney of 
the one particular type of floral anatomy in the Cichorieæ thus enables 
us to eliminate definitely Tussilago Farfara as an intermediate type. The 
vascular supply of the bilabiate corolla seems to vary with the width of 
the anterior lip, and the single main strand of the very narrow lip in 
Tussilago Farfara is to be considered with the other variations mentioned, 
such as the increase in number of the bundles when the anterior lip is wide, 
us developed in response to the needs of the corolla. 
Acknowledgments are due to Professor M. C. Potter for access to books 
and periodicals. 
* А curious difference between these male florets and the female ray florets is the very 
complete protective modification of the free margins of the petals. In the male florets the 
marginal epidermal cells are elongated to form tooth-like protuberances which in the bud fit 
exactly into those of the adjacent margins even up to the extreme tips of the five lobes, 
while no such protective device is present in the ray florets, where from a very early stage 
the style is free and unprotected by the corolla. This may be due to the archesporium 
being the region which requires protection. 
