3i6 
Lee.- — Observations on the 
Gaillardia aristata , Pursh. Seedlings 4 -6 cm. long, with prominent 
cotyledons and very short hypocotyls. Transition exactly as in Charieis 
heterophylla. 
Tagetes erecta , Linn. Seedlings 5-6 cm. long with narrow, rather 
fleshy cotyledons. 
The transition, first described by Gerard ( 5 , p. 369), is similar to that 
described for Heliopsis laevis , Seedling A , the following being the chief 
points of difference : the strands produced by fusion of the laterals from the 
cotyledons gradually die out while still some distance from the centre of 
the hypocotyl. Near the base of the latter they reappear internally to the 
lateral phloem groups, only to disappear finally in the root, which then 
possesses a diarch arrangement. Thus, a semi-tetrarch structure, with four 
protoxylem groups and two or four phloem masses, is present for a long 
distance. 
T. patula , Linn. Seedlings externally like those of T. erecta. 
Transition similar in all details to that in Heliopsis laevis , Seedling B. 
Tribe VII. Anthemideae. 
Anacyclus Pyrethrum , DC. Seedlings about 6 cm. long. Transition 
as in Tridax procumbent, a diarch root being produced. 
Achillea pyrenaica , Sibth. Seedlings about 3 cm. long, each with two 
equal cotyledons, which, uniting at the base, produce a cotyledonary tube. 
The transition is almost exactly as in Charieis heterophylla. 
Matricaria eximia ? Seedlings about 2 cm. long. Vascular strands 
very minute, with transition as in Charieis heterophylla. 
Tanacetum vulgar e , Linn. Seedlings generally 4-5 cm. long, with 
comparatively large seed-leaves, and a very long cotyledonary tube. 
Transition is similar to that in Charieis heterophylla , but the fused 
laterals disappear in the cotyledonary tube. In one seedling which was 
larger than the rest, however, the lateral (cotyledonary) strands persisted 
for a considerable distance in the hypocotyl. 
Chrysanthemum carinatum, Schousb.) ~ ... . . , , 
C. Sibthorpii ? I Seedhngs slender - 4 ~ 6 cm - Iong ; 
cotyledons equal in size and comparatively fleshy. Transition almost 
exactly as in Charieis heterophylla , except that the intercotyledonary 
bundles may join those in the cotyledonary plane by moving in a clockwise 
direction, or may disappear before they reach the centre of the hypocotyl. 
C. Parthenium Bernh., ^ wh i ch are slightly larger 
6. viscosum , Desf. J 
than in the last species, the general course of events is the same, but the 
intercotyledonary strands generally travel to the centre of the hypocotyl, 
where the xylem portion forms the core of the diarch plate. In all the 
