founded on the Structure of their Seedlings. 53 
Eight species in all, representing five genera, have been 
examined, and will now be described in more or less detail. 
The seedling of Nigella damascena has been chosen as the 
type of vascular structure in this family by MM. Gerard (13), 
Dangeard (9), and Sterckx (38). There is nothing to add 
to their account of the anatomy of the hypocotyl in this 
species. An outline of it will be sufficient here. The vascular 
symmetry agrees in all essentials with that of Delphinium 
Requienii , and Diagram IX represents the transition from 
a stem to a root structure within the hypocotyl of both 
species. 
The three main bundles of the blade enter the petiole 
of each cotyledon, but soon unite to form a single massive 
bundle. This is particularly clear in Delphinium Requienii 
because, owing to the greater length of the petioles in this 
species, the union of the lateral bundles with the midrib takes 
place at some distance above the insertion of the cotyledons 
on the axis. At the level where it is joined by the lateral 
bundles the midrib is still to all appearance single. 
Near the base of the petiole, the single massive bundle 
of each cotyledon opens out into a double structure precisely 
similar to that formed by each cotyledonary trace in Anemar- 
rhena (Diagram VI). Both in Nigella and Delphinium however 
the double character of each bundle is very clear a short 
distance above the insertion of the cotyledonary traces on the 
plumular stele. M. Dangeard is so much struck by this 
feature in the cotyledon of Nigella that he does not hesitate 
to describe its petiole as containing two bundles (9, p. 85 ). 
In this interpretation of the structure I entirely agree : the 
vascular symmetry of this genus and those which resemble it 
is much simplified by supposing four cotyledonary traces 
to enter the root-stele. A similar assumption has already 
been made with regard to the two traces of the cotyledon 
in Anemarrhena (p. 6 ). 
The resemblance between the vascular symmetry of Del- 
phinium or Nigella and that of Anemarrhena is obscured 
at the first node from a very simple cause. The traces of the 
