76 MR. R. H. COMPTON: AN INVESTIGATION OF THE 
CESALPINIOIDE, 
This sub-order comprises a majority of species of arboreal habit, and all 
whose seedlings have been examined up to the present time are shrubs, 
trees, or lianes. 
The embryo is almost invariably straight, and is frequently enclosed in a 
large amount of endosperm, characters which ally the sub-order with the 
Mimosoide: in contrast to the majority of the Papilionate. Germination is 
usually epigeal, but certain of the Bauhiniew show a tendency to become 
hypogeal, and in the Eu-Cesalpiniex it appears that hypogeal germination 
is frequent. In some epigeal seedlings a prominent collar is found at 
the base of the hypocotyl, just as in many Mimosoidez (e. g. Parkinsonia 
aculeata, Petalostylis labieheoides). 
The seedlings vary greatly in size and form and in the relative develop- 
ment of parts. Some of them are small with slender hypocotyls and thin 
cotyledons (е. g. some Cassie) ; others have very stout hypocotyls with 
epigeal cotyledons of moderate size (e. g. Intsia africana) ; while others have 
relatively exaggerated cotyledons, and hypocotyls of comparatively restricted 
dimensions (е. g. Guilandina Bonducella): in certain cases the diameter 
of the hypocotyl diminishes very conspicuously from below upwards 
(е. д. Labichea lanceolata, Petalostylis labieheoides) ; in most seedlings some 
such tapering occurs, but not to the marked degree observed in these species. 
It may be noticed that this sub-order shows certain parallels with the 
Mimosoidew in the characters of their seedlings. The Cassiez, for instance, 
may be compared with the Acaciew and Eu-Mimosez both in external form 
and in structure. The Eu-Cesalpiniee show similarities to the Inge, 
especially in the occurrence of both epi- and hypogeal forms; while the 
Amherstieze may be put side by side with the Adenantherem. 
The type of symmetry is remarkably uniform, tetrarchy being the general 
rule. Diarehy has, however, been recorded by Van Tieghem and Douliot 
(1888, p. 173) as occurring in Saraca and in Cercis; and Bauhinia yunnanensis 
shows diarchy in the root gradually changing to tetrarchy higher up the 
axis. Bauhinia racemosa exhibits some variety ; some seedlings exhibiting 
tetrarch, others hexarch roots; the relation of these different types to one 
another is quite clear (p. 15). 
The level of transition varies from * high” in Petalostylis labicheoides, the 
slenderest seedling studied, to what is perhaps the most pronounced type of 
low transition in the massive seedlings of Intsia africana, Tamarindus indica, 
«е. Tn these last the hypocotyl—even the upper part of the root—shows a 
stem-structure without any clear signs of root-like anatomy. The majority 
of seedlings, however, while exhibiting transitions best classified as low, do 
not attain the same degree of “lowness” as these large members of the 
Amherstiee, The Cassie (excepting Ceratonia Siliqua) show a very 
