EDMUND W. SINNOTT 
Ran ALES. 
The nodal structure of the Ranales is extremely various but seems 
to have been primitively trilacunar. The three genera Trochodendron, 
Tetracentron and Euptelea, included by Engler under the family 
Trochodendraceae, are characterized, respectively, by five, three and 
one traces and gaps. The Cercidiphyllaceae (Cercidiphyllum) are 
trilacunar. Among the Ranunculaceae, the presumably more primi- 
tive sections of the family (the Paeonieae and Helleboreae) are for the 
most part trilacunar. Such a condition distinguishes Paeonia (fig. ii), 
Caltha, Coptis, Delphinium and sometimes Aquilegia. Forms in which 
the primitively follicular ovary has been much reduced, as Actaea, Xan- 
thorrhiza (fig. 12 and photo. 5) and Cimicifuga, have the base of the 
leaf supplied with a very large number of strands inserted separately 
around most of the periphery of the stem. Such a condition is present 
also in the Anemoneae (Ranunculus, Anemone and Thalictrum), which 
from their single-seeded fruits are regarded by Engler as the most 
highly specialized members of the family. Clematis is the only member 
of this subfamily with a trilacunar node. The trilacunar condition 
therefore seems to have been primitive for the Ranunculaceae; and 
reduction of the ovary and amplification of the nodal system have 
apparently progressed together. The Lardizabalaceae (Akebia and 
Sinofranchetia) are trilacunar. Among the Berberidaceae, Berberis 
communis and many other species are trilacunar but others, particu- 
larly B. aquifolium, may have as many as eleven bundles passing off 
to the leaf base. In Epimedium there are seven strands and gaps. 
The Menispermaceae seem to be exlusively trilacunar. The Mag- 
noliaceae are perhaps more variable in nodal structure than any other 
family of dicotyledons. Illicium, Schizandra and Kadsura are uni- 
lacunar; Drimys and Tetracentron are trilacunar, and Liriodendron, 
Magnolia and Michelia are multilacunar. The Calycanthaceae are 
all trilacunar. The rest of the sub-order Magnoliineae which were 
observed (the Anonaceae, Myristicaceae, Monimiaceae, Lauraceae and 
Hernandiaceae) are entirely unilacunar, but in every case the leaf- 
bundle is three-lobed or tripartite (photo. 3), indicating that the nodal 
type was originally trilacunar. 
The nodal structure of the Ranales seems to have been primitively 
trilacunar and to have progressed both toward amplification and toward 
reduction. The group as a whole is more variable in this respect than 
are most orders, a circumstance which seems to favor the idea that 
