156 BRITISH PLANTS 
run a few inches along the ground, root, and at their 
extremity form new plants. Thus, in the autumn, a parent- 
plant may be seen surrounded by a circle of descendants. 
When the old plant dies the stolons perish, and the off- 
spring become independent. Creeping stems: in some 
prostrate plants the ordinary stems and shoots creep along 
the ground and root at the nodes. By the dying away of 
the main stems the branches are liberated as separate 
plants—e.g., ground-ivy, creeping Jenny. 
3. Bulbs and Corms (p. 111).—These are compressed 
shoots or buds, capable of rooting, and, by reason of the 
food-reserves they contain, capable of independent life. 
In bulbs the food-material is stored in swollen leaves, the 
stem being relatively small ; in corms the stem becomes 
swollen and filled with food, the leaves being reduced to 
scales which enclose and protect the stem. In both cases 
new plants arise as buds in 
the axils of leaves on the old 
bulb or corm, but their de- 
velopment proceeds along dif- 
ferent lines in different plants. 
In the tulip (Fig. 59) the 
bulb consists of a short axis 
bearing four or five thick, 
eh loosely-arranged scale-leaves 
ae? Gnas m which entirely ensheath the 
stem ; these are enclosed by 
a single thin, dry, brown scale, which effectively prevents 
evaporation of water from the storage-leaves. The centre 
is occupied by the flowering shoot and the young foliage- 
leaves. In the spring, as the flower and leaves grow into 
the air, the food passes into them, and the fleshy food- 
scales shrink somewhat. A bud in the axil of the inner- 
most scale now begins to grow. Surplus food in the 
scale-leaves, together with food manufactured in the 
foliage-leaves, pours into it, and the bud gradually assumes 
the form and proportions of a bulb. By the time this 
new bulb has completed its development the flower, 
foliage-leaves, and old scale-leaves have withered. In 
this way a new bulb is produced each year. In the larger 
bulbs more than one bud may develop, and in this way 
multiplication is secured. The production of several 
buds instead of one is insured by removing the flowering 
4) Dm heh 
Nila 
