Seedling Anatomy of Certain Sympetalae . II. 321 
Serratula tinctoria , Linn. Seedlings 9-12 cm. in length, with long, 
almost linear cotyledons, and a very extended cotyledonary tube. The 
main features of the cotyledons and of the rearrangement of the vascular 
bundles are very similar to those in Charieis heterophylla , but the region of 
transition is much longer. In some cases the intercotyledonary strands are 
retained in the centre almost to the root-tip. 
Centaurea macrocephala , Puschk. Seedlings both externally and 
internally similar to those of Silphium perfoliatum. A tetrarch root with 
a large pith is first produced, which lower down decreases in area in 
transverse section, so that the pith becomes smaller and the vascular tissue 
takes up a position nearer the centre. The xylem in the intercotyledonary 
plane now becomes reduced. One by one the lignified elements disappear, 
the phloem groups fuse in pairs laterally, and a diarch root is produced. 
C. babylonica , Linn. Seedlings not so large as in the last species, and 
vascular strands correspondingly smaller. The chief features of the transi- 
tion are similar to those in Crupina Crupinastrum . The intercotyledonary 
bundles decrease immediately after their formation by fusion of the four 
lateral strands, and when only slightly rearranged they pass inwards and 
fuse with the cotyledonary bundles. At quite a high level, a diarch 
root-structure obtains. 
Carthamus tinctorius , Linn. In all essentials the seedling of this species 
(which was also examined by Gerard ( 5 , p. 367), is like a much reduced 
one of Centaurea macrocephala , exhibiting exactly the same features as 
Centaurea babylonica. The seedling is not nearly so massive as that of the 
former species, and the vascular bundles are very much smaller. In the 
very long cotyledonary tube the extreme lateral strands fuse in pairs, and 
almost immediately die out or fuse with the other lateral bundles. The 
latter next fuse in the same order, and of the four strands which enter 
the hypocotyl, the two very small ones in the intercotyledonary plane 
immediately pass to the centre to form the core of the diarch root. Thus 
there is only the slightest trace of a tetrarch structure. At a fairly high 
level the midrib strands undergo rearrangements which result in the 
production of a diarch stele. 
Tribe XIII. Cichorieae. 
Cichorium Intybus , Linn, (garden variety). Seedlings short (not more 
than 5 cm. long) and rather stout. The cotyledons are broad and ovate in 
shape, and fuse at the base to form a fairly long cotyledonary tube. In each 
seed-leaf there is a definite midrib with smaller veins which run more or less 
parallel with the margin. These join on to the midrib very gradually, the 
last fusion occurring in the cotyledonary tube. Only two bundles enter 
the hypocotyl, and these become rearranged according to Van Tieghem’s 
Type 3 - 
