CH. I. BY TPIE SUEFACE OF THE ROOTS. 25 



and excrete from all parts which are exposed to 

 drought. 



The radishes had been grown in very light mould, 

 so that, by passing the fingers into it in taking the 

 radishes up, I beheve not a rootlet, main or lateral, was 

 broken. The whole of the roots were left on No. 3, 

 and much earth adhering to the side-roots of some. 

 The weather was very favourable for the first week, the 

 wind south or south-west, the thermometer about tem- 

 perate, with constant heavy showers. For this reason, 

 none of the experiments were watered for the first 

 fortnight. On the 21st the wind got to the north, and 

 the weather was sunny and dry. But, ere this, nearly 

 all No. 3 were defunct. On the 29th, after a week's 

 drought, some of the leaves of Nos. 1 and 2 looking 

 flagging, the experiments were all watered. Care was 

 taken that the water should only fall on the earth, 

 without touching a leaf, in order to make certain that 

 the revival (which took place) was caused solely by the 

 absorption of moisture by the rootless bulbs — nay, in 

 the case of No. 2, by the rootless HALF-bulbs. 



On the 28th of May, when the experiments were 

 between six and seven weeks old, I turned No. 1 and 

 No. 2 into the open ground. On taking off the pots I 

 found the roots in both cases matted round the balls of 

 earth, and they had grown through the holes of the 

 flower-pots. Can it be supposed that these long roots 

 are useful to their plants only by their ends ? Can it be 

 supposed that the grand systems of roots of forest-trees 



