286 PHYSIOLOGICAL BOTANY. r \KT1I. 



have already given several instances of the close affinity 

 which subsists between the various foliaceous appendages 

 on the stem (art. 85.), and have further mentioned the 

 community of origin in the leaf-bud and flower-bud. 

 There also exists an evident and striking affinity be- 

 tween the leaf-bud and the embryo, inasmuch as 

 each of them when detached from the plant on which 

 they were formed, is capable of becoming a perfect in- 

 dividual. The chief distinction between them consists 

 in the former first developing its ascending organs and 

 then its descending organs, whilst the embryo first 

 emits the root and then develops the plumule. 



(-<)-.) Proliferous Flowers. In " proliferous " 

 flowers especially, the identity of their origin is strik- 

 ingly exhibited. In these instances, every bud which 

 in ordinary circumstances would have been developed as 

 a flower, assumes the characters of a young plant. In 

 the onion tribe this description of monstrosity is very 

 common, and the little flowers which are aggregated 

 into heads become small bulbs, and germinate as young 

 plants even whilst they are still attached to the summit 

 of the stem. The same fact very often takes place in 

 certain grasses, and especially in some of those which 

 affect a mountainous situation. This appears to be a 

 provision of nature, to furnish an additional security 

 against the chance of failure in the seed, at an elevation 

 whore the cold might offer a serious obstacle to its being 

 perfected. 



(2f)3.) Bud* on Leaves. The Bryum rnlju-inuni 

 furnishes one of the most satisfactory examples of the 

 connection which exists between the bud and the em- 

 bryo. Its leaves are very fleshy, and when they are 

 placed in a moist situation, and even whilst they are 

 still attached to the stem, little buds are formed at the 

 bottom of the crenations on their margins (fig. 1()8.), 

 and these buds soon develop into perfect plants. Now 

 if we only suppose a leaf of this plant to be longitudi- 

 nally folded inwards, and that its margins become 

 grafted together, the buds will then correspond to the 



