44 SOUTH AFRICAN FLOWERING PLANTS. 



leaf-blades are seen, one on each side of it. All the 

 rest are the bulb-scales ; they completely wrap round 

 each other, and are called tunicated, so, when cut across 

 they look like rings. They are really the bottom parts 

 of the leaves without the blades above, a, a are little 

 bulbs or bulbils, which, when sufficiently large, will 

 fall olT and become new plants. The bulk of the bulb 

 is therefore composed of bulb-scales. There is a kind 

 of onion growing in the intensely hot sand of the 

 desert near Cairo, which, to keep the innermost scales 

 fresh, hardens the outer ones till they feel like wooden 

 coverings. The temperature of the sand may be 130° 

 Fahr. 



Many bulbs have scales which do not surround the 

 stem, but grow like the scales of a fir-cone, overlapping 

 one another, as do those of lilies. 



A corm, as shown in Fig. 22, of a Glad'iohis con- 

 sists mainly of the globular base of the stem, &; the 

 scales, being dried up, form a thin covering, d, c 

 being the flowering stem in the middle. The new corm, 



b, is formed on the top of the old one, a. This 

 supplied the nourishment for the flower, and then 

 shrivelled. The fresh leaves then set to work to make 

 starch, which is stored up in the cells of the new corm, 

 which keeps getting larger to receive it. 



Fig. B is the corm with the skins removed ; a, h, 



c, d, are the same as in Fig. A, but y is a bud on 

 the top of the new corm, which will flower next year ; 



