174 Leaves and their Work 



by others. That is to say, they live for a time, seedlings 

 — upon the material stored in their seeds — bulbs, upon 

 the material stored in the bulbs, which are huds, not 

 roots— all of which has been prepared by means of leaf- 

 green, and in the light. 



In the case of bulbs, the leaves go on collecting food 

 long after the plants have done flowering, in readiness 

 for the blossoms of the next spring ; and if the leaves 

 are cut off before they have finished their work, the 

 bulbs shrivel, and have not the means of supplying 

 next year's blossoms at all. The autumn crocus comes 

 up and blossoms, without its leaves, but it is dependent 

 upon them for the means of putting forth its blossoms ; 

 for the leaves have been busy months before, in the 

 spring, storing the necessary material in the bulbs. 



Seedlings, in like manner, when first they germinate 

 under the soil, before they are provided with leaf- 

 green, live upon the food stored up within them ; but 

 if, when this is exhausted, they are still kept in dark- 

 ness, they will not only remain yellow, but will lose, 

 instead of gaining in weight, and that though their 

 roots may be busy collecting food from the soil. 



But why, it may be asked, should they lose in weight ? 

 Without carbon they cannot, of course, use the food 

 from the soil, they cannot grow; but provided they 

 have water, why should they not remain as they were ? 

 What are they doing to make them lose weight ? 



Well, they are doing just what all living things do, 

 and must do, if they are to remain living ; they are 

 breathing 1 breathing as animals do, though they have 

 no lungs, and though they breathe very much more 

 slowly. That is to say, they are taking in air. 



In breathing, as has been said, part of the oxygen of 



