38 Principles of Plant Culture. 
face of fine soil in a propagating frame, in which the air is 
kept very moist and the surface of the soil never becomes 
dry. 
54. The Plantlet is Visible in the Seed. If we boil 
seeds of the four kinds shown in Figs. 7 to 10, or of other 
kinds, in water until they are fully swollen, and then care- 
fully dissect them with the forceps and needle, using the 
magnifying glass when necessary, we may observe that the 
plantlet is present, compactly folded up, in the seed. Ger- 
mination (28) is really little more than the unfolding and 
expansion of this plantlet. The plantlet, as it exists in the 
seed, is called the embryo (em’-bry-o). 
39. The Endosperm®* (en’-do-sperm). From the sec- 
tion of the corn grain shown in Fig. 12, it appears that, in 
Fic. 12. Cross section of germinating Indian corn grain. A. endosperm; 
Cot. cotyledon; Cau. hypocotyl; Pl. plumule. Slightly magnified. (After Frank). 
to the unaided eye. The dust that escapes from a puff-ball when it is squeezed, 
or from a bunch of corn smut consists of the spores of these plants. Spores usu- 
ally consist of a single cell, in which respect they differ materially from seeds, 
which contain a more or less developed plantlet (54). 
* Called also albumen. 
