Lily-kin and Rose-kin 131 
The corn at six weeks old is more sturdy than 
when it first rises above ground, but this is mainly 
because the second joint of the stem is larger than 
the first, and the third larger than the second. So 
if we push away the earth from the base of grow- 
ing corn we find that the portion closest to the 
ground is more slender than the portion above. 
But the increase in the diameter of the corn-stalk, 
lily-stem, or palmetto-trunk is entirely limited 
to the earliest period of growth. Some of the 
oldest palmettos in Florida are noticeably slen- 
der. 
Among all the lily’s many kin there is but one 
native plant which grows stouter as it grows old. 
This is the yucca or bear-grass of the Southern 
States, which is interesting to botanists as a con- 
necting link between two great classes of plants, 
for it is a monocotyledon in everything except its 
mode of growth, and in that it resembles the di- 
cotyledons. For the kin of the rose grow stouter 
and sturdier with every year of life. 
The main stem and older branches of a rose- 
bush have a tough bark, which peels off readily in 
strips. If we examine this carefully we find that 
it consists of two portions. The outer layer is 
thin and colorless, and in an old rose-bush it is 
