252 NATURAL HISTORY. 



531. The sixth rule shall be, to make plants 

 grow out of the sun or open air ; for that is a great 

 mutation in nature, and may induce a change in the 

 seed ; as barrel up earth and sow some seed in it, 

 and put it in the bottom of a pond, or put it in some 

 great hollow tree : try also the sowing of seeds in 

 the bottoms of caves; and pots with seeds sown, 

 hanged up in wells some distance from the water, 

 and see what the event will be. 



Experiments in consort touching the procevity, and 

 lowness, and artificial dwarfing of trees. 



532. It is certain, that timber trees in coppice 

 woods grow more upright, and more free from 

 under-boughs, than those that stand in the fields : 

 the cause whereof is, for that plants have a natural 

 motion to get to the sun ; and besides, they are not 

 glutted with too much nourishment ; for that the 

 coppice shareth with them, and repletion ever hin- 

 dereth stature : lastly, they are kept warm, and that 

 ever in plants helpeth mounting. 



533. Trees that are of themselves full of heat, 

 which heat appeareth by their inflammable gums, as 

 firs and pines, mount of themselves in height without 

 side-boughs, till they come towards the top. The 

 cause is partly heat, and partly tenuity of juice, both 

 which send the sap upwards. As for juniper, it is 

 but a shrub, and groweth not big enough in body to 

 maintain a tall tree. 



534. It is reported, that a good strong canvas, 

 spread over a tree grafted low, soon after it putteth 



