154 ORGANIC METAMORPHOSIS OF LEAVES 



passes away, and other flowers occupy its place. Its form 

 is seen no more until the cold, moist conditions of the 

 early part of the year again prevail. Then, from those 

 germs which Nature ever carefully preserves, it again 

 springs into being, to perform its allotted part in the great 

 organism of the Universe. 



In works on descriptive botany, it is usual to employ 

 certain signs to designate the different duration of plants. 

 These signs are those used by astronomers to represent some 

 of the heavenly bodies. Thus, annual plants are represented 

 by the sign of the sun 0, because the earth revolves around 

 that star in a year ; biennial plants by the sign of Mars $ , 

 because that planet performs its revolution about the sun 

 in two years; perennial plants by the sign of Jupiter if, 

 because Jupiter is nearly twelve years in going round the 

 sun ; and ligneous plants by the sign of Saturn J? , whose 

 revolution about the sun is accomplished in about twenty- 

 nine and a-half of our years. 



Now herbaceous plants, whether annuals, biennials, or 

 perennials, like the trees which overshadow them, during 

 the vegetative period of their life, ramify and branch ; and 

 there is the same continual loss of vegetative power by their 

 branches from generation to generation until the ramify- 

 ing power is exhausted ; so also their branches, like those 

 of trees, are only repetitions of the whole plant on a smaller 

 scale. Their branches, however, differ from those of trees 

 in this particular, that they are without the folia tegmentia, 

 or covering leaves, and have, therefore, no means of security 

 organized to protect them during the winter months. To 

 herbaceous plants, a humbler task has been allotted in the 

 household of Nature. It is not her intention to preserve 

 them, or consolidate their fabrics, and therefore the frosts 

 of winter are permitted to despoil them of their beauty, 

 and to sweep them into one common grave. Their branches 

 develope from what Henfrey has very properly called " open 

 buds," one, two, and sometimes even three generations 

 being formed during the same season. This necessarily 

 rapidly exhausts the vegetative powers of the organism, 



