Roots and its Influence on the Ecesis of Plants in Swamps . 1 7 
developed on some of the roots in aerated water. In the plant in soil wet 
by capillarity roots also developed at the surface. In this case the upper 
roots made the greatest growth, but all the lower roots were living. In 
moist garden soil root development was extensive, reaching to all parts of 
the pot with an abundant development of root-hairs. 
Experiments with Pelargonium and Coleus. 
A similar experiment was carried out with Pelargonium. On plants 
with the roots submerged and not aerated, the leaves began to turn yellow 
in ten days or two weeks. Shortly afterwards the leaves dropped. The 
behaviour of the roots of Pelargonium was similar to that observed in 
Impatiens. In all cases where the roots were submerged, whether or not 
the water was aerated, new roots developed at the surface, while the sub- 
merged roots died. This was also found to be true of the roots of Pelar- 
gonium in soil wet by capillarity, although with Impatiens the lower roots 
remained alive. After the development of surface roots the plants again 
began to grow and produce new leaves. Root development in ordinary 
moist soil was abundant. Pelargonium was found to be less responsive than 
Impatiens in that it did not show wilting as clearly or as quickly. Loss of 
colour was the first sign of distress. Soon after changing colour the leaves 
usually dropped. 
Plants of Coleus Blumei potted in soil, with the roots submerged, 
showed signs of distress in one or two days. The first evidence was the 
wilting of the leaves. The leaves after remaining in a more or less wilted 
condition a few days dropped off, until only two or three small leaves near 
the top of the stem remained. After ten days or two weeks new roots 
were always found to have developed from the stem at the surface of the 
water. Plants in moist soil developed normally. 
Experiments with Vicia Faba . 
An experiment with Vicia Faba was tried as follows : Seeds were 
planted in batteries of six pots each containing garden soil, peat, and 
Sphagnum respectively. As soon as the seedlings had broken through the 
ground the cotyledons were removed from two plants in each set. From 
each battery of six, two plants with cotyledons and one with cotyledons 
removed were placed in vessels of water so that the roots were fully sub- 
merged. The other three pots of each battery of six were kept moist, but 
never to saturation. In four or five days all plants, the roots of which had 
been submerged, began to wilt. This condition continued for a week or 
more in varying degree according to the temperature of the greenhouse. 
In all cases, however, the plants lived. The plants were permitted to grow 
ten weeks ; at the end of this time it was noted that the plants in soil with 
the roots not submerged Hhd grown most, those in Sphagnum least, and 
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