PLANTS CARRY LIFE INSURANCE 135 
mon vegetables, such as Irish potatoes. These po- 
tatoes, if cut into pieces, without having their “eyes” 
damaged, and placed in the right kind of soil and 
climate, will soon develop into new potato plants. 
Not many bulbous plants have “eyes”: that is, the 
places from which the new plants spring, as in the 
potato; but those that do not usually develop sep- 
arate bulbils. That part of the potato other than 
the eyes is the food insurance that the parent potato 
has stored up to feed the new plants until they are 
able to get nourishment from the soil. 
Some plants protect their food insurance by 
burying their stems underground; the stems thus 
buried are known as rhizomes. Solomon’s seal, 
sedges, iris—all these bury their stems under the 
soil; but other plants, many of which grow in the 
tropics, like tree-ferns, owing to the mild climate do 
not need to conceal themselves from the inclement 
weather by burrowing underground. 
In bulbs and rootstalks which are protected un- 
derground, not only a sufficient quantity of food- 
material is saved to feed the plant, but often enough 
is contained to form new bulbils. Especially is 
this true of lilies, tulips, dahlias, crocuses, and hya- 
cinths. 
The century-plant of the western plains stores 
up food for a number of years, preparatory to blos- 
