256 PRINCIPLES OF BOTANY, ETC. 
§ 248. 
Plexcoblastae are those in which the cotyledons ap- 
pear above ground in two halves, and change into 
leaves, which are of a different shape than the rest 
of the leaves. They are elliptic in the species of 
Phaseolus; linear in the umbellatae, and in the 
Plantago; cordate in the plants of the sixteenth 
class of Linnzeus; inversely cordate in those of the 
15th class; reniform in the ringent plants;  club- 
shaped, and at the point variously intersected, in the 
lime-tree. 
§ 249. 
Geosblastae, 1 call those which keep the substance 
of the cotyledons under ground, e. g. the vetch-pea, 
the gramina, lilies, &c. They are of a double kind. 
Rbhizoblastae, where the seed has a rostel, and 
shoots down a2 straight root, as in most plants. 
Arhbizoblastae, when the seed wants the rostel, as 
in some water and parasitic plants. 
§ 250. 
Sphaeroblastae, are those whose cotyledons do 
not divide in two, but come out of the ground in 
form of little globules fixed upon a small stalk, and 
have the plumula on their side. This we meet with 
in Juncus bufonius, and some plants related to it. 
Several botanists who were unacquainted with this 
singular modification of germination, have mistaken 
the above-mentioned plant for a new one belonging 
to the 24th class of Linneeus. 
