326 ON SEEDLINGS 



rule, but there are cases where it is inferior as in Suriana and 

 <}neoridium. In Dictyoloma and Koeberlinia they are numerous, 

 ascending, with the raphe dorsal. The fruit is drupaceous or 

 dry and indehiscent,' sometimes with a woody endocarp as 

 n Cneorum and Simaba, or it is capsular and dehiscent as in 

 Dictyoloma and Brunellia, or samaroid as in Ailanthus and 

 Soulamea. The seeds are generally solitary and pendulous, 

 with a membranous or sometimes crustaceous testa as in 

 Cneorum. Endosperm is copious and fleshy, or scanty, or al- 

 together wanting. The embryo is straight with flat or plano- 

 convex cotyledons, more or less semiterete. In rare cases they 

 are twisted, and in the large-seeded Simaba they are thick, 

 fleshy, and plano-convex. 



A longitudinal section of one of the cocci of Cneorum tri- 

 coccuni shows the curious manner in which the seed and 

 embryo are curved so as to accommodate themselves to the 

 interior of the bony endocarp. The testa is not folded, while 

 the tegmen containing the fleshy endosperm and the embryo 

 is doubled up on itself. A transverse section of another coccus 

 shows two seeds occupying the cavity. In Dictyoloma the 

 seed is winged. The fruit of Ailanthus glandulosa consists 

 of one to five samaras, but, in Britain at least, only one is 

 usually brought to maturity although two are not unusual. 

 The samara is oblong or oblanceolate, nearly straight on the 

 ventral edge with a small indentation above the middle, where 

 the solitary seed is located, and more or less rounded on the 

 back, laterally compressed and membranous. The seed lies 

 in a slightly elevated cavity of the samara, and is obliquely 

 pendulous, anatropous, and laterally flattened. The embryo 

 lies in the broader plane of the seed, embedded in endosperm, 

 which it nearly equals in length and width. The cotyledons 

 are obovate, nearly flat, and conform to the shape of the seed, 

 with their edges to the placenta. The superior radicle is 

 several times shorter than the cotyledons. 



Seedlings. This Order is mainly tropical, and with excep- 

 tion of a few species of some medicinal importance, together 

 with the hardy Ailanthus glandulosa and Cneorum tricoccum, 

 are seldom seen in a living state in this country, consequently 

 seedlings seldom come under observation. The cotyledons of 



