88 MR. R. H. COMPTON: AN INVESTIGATION OF THE 
In the majority of the tetrarch species, as described by Dodel (1872), 
Gérard (1881, p. 346), and the present author, all four root xylems pass 
into the cotyledons. This appears to be the case both in epigeal and 
hypogeal germination. Van Tieghem (1871, p. 219), however, mentions 
that in the hypogeal Dolichos lignosus the two intercotyledonary protoxylems 
of the root are plumular. In Voandzeia subterranea, with a higher symmetry 
than tetrarch, one or more primary xylems of the root may connect directly 
with the epicotyl. 
A characteristic feature of the seedling is the presence in the inter- 
cotyledonary plane of a pair of primordial leaves, whose shape often differs 
markedly from that of the mature foliage. The vascular supply of each of 
these leaves is sometimes double; a bundle is inserted on the edge towards 
the minor axis of each cotyledon trace in the upper part of the hypocotyl; 
these approach one another in pairs, as they ascend into the epicotyl, and 
fuse in the intercotyledonary plane ; the median bundles of the primordial 
leaves show, as a result of this origin, a double appearanee for some distance 
along the first internode. (See Phaseolus Hernandesii.) 
The transition is of a characteristic type in the larger Phaseoleæ ; it has 
been thoroughly described by Dodel (1872). А featuro of frequent 
occurrence is the presence in the hypocotyl of a certain number of coty- 
ledonary intercalated bundles or Zwischenstringe ; these take their origin in 
the zone of precocious secondary thickening developed at the collet region in 
relation to the much-branched roots, and do not form primary connections 
with the main root. Similar structures have also been observed in Abrus 
precatorius and in the Dalbergiez, a closely allied tribe. 
Tannin-sacs are very abundant in the hypocotyl of most species ; Canavalia 
is, however, without them. Primary phloem fibres are also widely dis- 
tributed. ‘The level of transition is low in the large Phaseolines, Diocleinæ, 
and Erythrinine ; in other more slender species it is intermediate or 
intermediate-low. 
The tribe shows certain analogies with the Cæsalpinioideæ in the form and 
structure of its seedlings. In both groups we find epi- and hypogeal 
germination ; opposite primordial leaves ; large and medium-sized seedlings; 
occasionally a considerable distension of the lower half of the hypocotyl ; 
prevalent tetrarchy with occasional instances of higher types of symmetry ; 
low transitions in the larger, and somewhat higher transitions in the smaller 
seedlings ; occasional plumular traces in the root ; and sometimes signs of 
doubleness in the vascular supply of the primordial leaves. On the other 
hand, the prevailing habit of growth is very different in the two groups. 
