286 Chances of Life 



Australians have managed to do so. Yet Australia is 

 nearer than Europe, and the intercourse between the 

 two countries is much more close and frequent than it 

 is with Europe. Moreover, Australian seeds have been 

 purposely and extensively scattered in New Zealand, 

 among them being, we may be sure, the seeds of such 

 common kinds as those of the acacia and eucalyptus ; 

 yet none of these trees are to be seen growing wild. 



It is the same with our own garden-plants. How 

 many there are which, though they grow in the garden 

 without any special care, and bring abundance of seed 

 to perfection, yet never run wild, even to the extent of 

 appearing on just the other side of the wall or hedge ! 

 Yet it is impossible to suppose but that the seed is 

 often carried beyond these limits ; and weeds make 

 their way in without difficulty. 



In considering what becomes of the vast amount of 

 seed which is annually ripened, we must, of course, 

 bear in mind that a great deal is consumed as food — 

 luckily for us ; for if there were no seed-eating birds, 

 we should be overrun with thistles and other weeds. 

 Some seed also falls upon soil which does not suit it ; 

 some requires burying, and gets killed by remaining 

 exposed ; some cannot germinate without special pre- 

 paration of itself or the soil, or both ; still more, if 

 transported to a distance, will find the climate unsuit- 

 able. 



But in many cases want of space is the only obstacle, 

 and a very serious one it is. There is generally plenty 

 of room for weeds in a garden, and they are not slow 

 to take advantage of it ; for there is a good deal of' 

 crowding on the other side of the wall, where, in fact, 

 a constant struggle for existence is going on, and only 



