520 MR. JAMES SMALL ON THE 
Аз both Brown (2) and Don (4) remark on the facility with which the 
embryo can be extracted from the ovary adherent to the two strands which 
supply the style and which, according to these authors, continue without а 
break down the wall of the ovary, all the material was examined specially 
for such bundles. The stylar canal is lined with elongated cells and these 
become lignified and persist on the lateral sides of the mature ovary as 
conducting strands (fig. 2, diags. 2-3), but seem to act only secondarily 
as conducting tissue. Brown (2) gives the orientation of the stylar bundles 
correctly as antero-posterior and describes the ovarial strands as lateral. 
The lateral position of these strands, which are not a part of the true 
vascular system, is due to the developing embryo bursting the stylar canal 
on the anterior and posterior sides. The five corolla bundles divide at the 
base of the corolla lobes, and the halves unite to form five arches of con- 
ducting tissue along the margins of the lobes. 
In Taraxacum officinale, an example of the ligulate type, the course of 
events is very similar. The primary strand from the receptacle divides only 
into five * strands and the ovular supply (fig. 2, diag. 9). In this case the 
cells lining the stylar canal do not become lignified, and there is no trace of 
the bundles referred to by Brown and Don. There are again the upper and 
lower distributive centres, and a short distance from the former the posterior 
strand divides into three (fig. 2, diag. 10). The inner strand supplies the 
posterior stamen and the other two supply the margins of the ligulate corolla 
(fig. 2, diag. 11). According to Trécul (15) the point of fusion of these two 
marginal bundles varies from the upper distributive centre to some distance 
above the top of the ovary. 
In the ray or bilabiate florets of Calendula officinalis the single primary 
strand divides soon after or even before it leaves the receptacle, giving two 
large bundles and the ovular supply (fig. 2, diag. 12). Fusions begin 
towards the top of the ovary (fig. 2, diag. 13). The upper distributive 
centre shows new features (fig. 2, diag. 14) obviously dependent upon the 
absence of a posterior bundle, and from this centre arise the two stylar 
bundles, the two main corolla bundles, and two subsidiary corolla bundles 
(fig. 2, diags. 15 & 16). The cells lining the stylar canal become lignified 
aud persist as in Senecio vulgaris (fig. 2, diags. 12 & 13). The stamens are 
absent, and there is no trace of the bundles which presumably supplied them 
in the hermaphrodite condition of the floret. It is uncertain to what extent 
the vascular system of the bilabiate floret in Calendula officinalis is typical of 
ray florets in general. 
The disc florets of C. officinalis are very similar to those of Senecio vulgaris, 
except that only five bundles and the ovarial supply originate from the lower 
distributive centre instead of ten as in the latter species. 
* Trécul (16) gives usually four, rarely five, bundles. 
