NEW AND BEAUTIFUL ROCK PLANTS 97 



do not strike so readily as might be supposed from the 

 airy nonchalance with which this method of increase 

 is commonly prescribed. Neither the long shoots drawn 

 from the base of the central rootstock, nor the tips of 

 green young shoots, strike freely, and it is little use 

 trying them in the open ground. Even in a frame or 

 greenhouse the majority will probably go off. If cuttings 

 are to be tried it is well to put them in pans or pots 

 containing gritty soil and cover them with a handlight 

 in order to keep them close. Only under such conditions 

 will the majority of them make roots. Seeds may some- 

 times be collected if the plants are looked over about 

 midsummer. Fertile pods are of about the size and shape 

 of Cucumber seeds ; there may be many smaller ones, 

 but it is likely that these are infertile and on being slit 

 open longitudinally will be found to be seedless. The 

 seeds in the larger pods will be ready for gathering 

 when the latter turn yellow, and may be sown in a pan 

 of light soil in a frame. The commoner varieties may be 

 sown in the open ground in June. Where a good variety 

 of Aubrietia forms plenty of side shoots the longer ones 

 may be nicked with a knife, laid down, and covered 

 nearly to the tip with moist gritty soil in the hope of 

 encouraging the formation of roots. This process is 

 called layering, and if successful gives a much larger 

 stock of plants than can be got by division. Never- 

 theless, the rootstocks may be separated in the fall or 

 in early spring. On the face of things division is a ready 

 means of getting a large supply of plants if there is one 

 spacious clump at hand to draw from ; but it is found 

 on examination that all the outer shoots radiate from 

 a common centre, and that however large the clump 

 may be the rootstock itself is very small. For this reason 

 it is not possible to get a very large stock of plants by 



