THE PROPAGATION OF PLANTS, AVITHOUT SEEDS. 



30i 



tative and reproductive systems of flowering and flowerless plants has 

 often been observed. 



If a Pear-tree makes too much wood and foliage, the fruit may be 

 deficient, just as the Horse-radish increases its rhizomes and roots at the 

 expense of fruit, which is never formed. 



Many plants have actually become habituated to the practice of sub- 

 stituting leaf-buds for flower-buds. This occurs in plants usually called 

 "viviparous," as Onions, and Polygonum, as well as Grasses and Sedges 

 in the colder regions. 



In the case of corms and bulbs being formed in the place of flower- 

 buds, these are readily detached ; but in viviparous Grasses the whole 

 panicle falls to the ground, and the little buds then strike out at once. 



Not only can such vegetative but reproductive bodies take the place of 

 the entire flower, but they may be formed in lieu of ovules in an ovary. 

 Amaryllis and Crinum are well-known genera which bear them. Thus 

 M. Baillon writes* of Calostemina Cunninghamii, in which there is a 

 transformation of an ovule into a bulb :— " The chalaza thickens, and plays 

 the part of a ' plateau ' upon which are produced several adventitious 

 roots. The ovular coats replace bulb-scales ; while there grows up from 

 the embryo- sac a true bud, which escapes by the summit of the ovular 

 cavity and so forms a perfect plant." 



* Bitll de la Soc. Bot. de Fr. xxi. Eev. Bibl. p. 30. 



