Coral-root (Dentaria bulbifera), and in the Orange 
‘(Lilium bulbiferum) ; or in the place of the flowers, as in' 
142 PROPAGATION OF PLANTS. 
ter would be taken up for the nutrition of the young plant, 
and its nature completely altered. 
561. Artificial means have been employed to expedite the — 
process of germination, particularly by supplying the young a 
seed with certain bodies or salts, which yield uxygen readi- 
ly, or assist in procuring it from other bodies present, as the — 
peroxide of manganese, chlorine, &c. Humboldt is very — 
much in favour of the use of these substances, but there are 
others who doubt if any advantage is obtained by treating 
plants in that manner. Common cresses placed in a solution 
of chlorine, were observed to germinate in the course of six 
hours, whereas, when merely placed in pure water, thirty- 
six hours were required to produce the same result. 
562. Electrical action is also believed to exert consider- — 
able power over the same process, and M. Becquerel seems 
to have established the fact, that when seeds are excited by @ 
very weak positive electrical action, the germination is rapid, 
but does not take place if the electricity be negative. — : 
563. In hydrogen, nitrogen, or carbonic acid gas, seeds 
will not germinate. In oxygen, this process goes on with 
too great rapidity. The presence of agents which contr 
bute to the development of oxygen, in moderate proportions, 
as the solution of chlorine in water, is said to enable very 
old, hard, and dry seeds to germinate. é 
2. Propagation by Buds. 
564. Plants are propagated by buds in four different 
ways: 1. By means of the bulbs which grow at the base of 
the scales in the bulbous root, as in the Snowdrop or Lily; 
these bulbs are soon detached from the parent bulb, and be- 
come independent plants: 2, By means of the bulbils which 
grow upon the stem in the axilla of the leaves, as in the 
_ Mountain Garlic (Allium carinatum) : 3. By means of | 
5 buds or small bulbs which grow at the margins of the l¢ 
