ON PLANT PROPAGATION. 943 



pieces, when the germinating organ will show by its plump 

 nature and white colour if they are in good order. 



Preserving Seeds. — To preserve for a long period the germ- 

 inative qualities of seeds they must be kept in a condition neither 

 too dry nor too wet, say at a temperature not exceeding 45deg. 

 Fahr., and where outside weather will not have any effect on 

 them. Several seeds, like those of Aralia and Papyrus, which 

 lose their germinating properties very rapidly, must be sown 

 as soon as they have ripened ; but when they ripen in 

 autumn, it is preferable to wait, until the spring to sow 

 them. In this case they may be mixed with sand or soil and 

 placed in a ventilated bag, which must be kept as mentioned 

 above until sowing-time. In the case of annuals and numerous 

 soft-wooded plants, the seedlings of which are unable to withstand 

 any degree of cold, similar precautions should be observed. 



Seeds of Aquatics can easily be kept in the ordinary way 

 indicated above, with the exception of the beautiful Victoria 

 regia, whose seeds must always be kept in water. See Chapter 

 "On Aquatic Plants." 



Biennials should be sown about the middle of spring, so that 

 the young plants will be established before the winter, and ready 

 to flower in the following summer. • In the case of hardy, woody 

 plants, the seeds should be sown in the autumn, as they will not 

 suffer from the cold, and will commence growing with the 

 spring. 



Stratification. — By this method seeds which quickly lose their 

 germinative properties may be preserved. The direct action of air 

 has a very detrimental effect on seeds, and those requiring pro- 

 tection are mostly stratified as soon as they are collected. The 

 simplest way to do this is to take a receptacle of any sort 

 possessing some outlets to prevent any stagnation, and of a size 

 suitable to the quantity of seeds to be preserved. On the 

 bottom of it should be laid a thin bed of breeze (small pieces of 

 unburnt coke), and this should be covered with one of sand, on 

 which the seeds should be deposited as closely as possible. 

 Another layer of sand should now be added, then more seeds, 

 and so on until the pan is filled, when the whole must be 

 covered with more breeze to keep away worms. It is advisable 

 to stand the receptacle in the coolest place. As cellars are too 

 warm in winter, a good plan would be to bury it underground at 

 a sufficient depth to avoid frost. The soil placed on the top 

 must be arranged in such a way as to form a kind of cone to 

 keep off the water ; and this especially applies to tree and 

 vegetable seeds. Stratification is also useful for tropical and 

 sub-tropical seeds, which would otherwise lose their germinative 

 properties before their arrival here. Cocoa- and Coffee-tree seeds 

 must be stratified as soon as collected. 



