30 Soil-Makers 



scattered in this unlikely place ; and if we look at what 

 has been done in other similar places, we shall see that 

 it has not been wasted. 



Floating about in the air, invisible, but in countless 

 multitudes, are — what answer to the seeds of other 

 plants — the spores of those strange forms of vegetation 

 called lichens, which, except in towns, are to be seen 

 beautifying every old wall, roof, and tombstone. They 

 are so light that they cannot settle at all, except when 

 the air is still, and even then the least breath would 

 disturb them. 



But they are sticky, and this stickiness enables 

 them to cling- fast even to the bare rock. Once 

 settled, they begin to grow, and are the first traces 

 of vegetable life to make their appearance upon recent 

 streams of lava. They may truly be called 'traces,' 

 for the first-comers are nothing more than helpless- 

 looking stains, or dust, hardly noticeable except by 

 those on the look-out for them ; and one would have 

 said anything but dangerous to the rock, for they look 

 not only perfectly inactive, but entirely lifeless. 



Just so a stranger to the tropics, newly-arrived, 

 would see with perfect unconcern a single small ant 

 making its way across the floor of his room, a helpless 

 insignificant insect, which he could crush with a 

 finger. But the native knows better. He could crush 

 the one, but behind it is a mighty column of ants two or 

 three hundred yards long coming to take possession of 

 the house, and there is nothing to be done, as he knows, 

 but to give it up to them and retreat for the time. The 

 ants come and go again when their work is done ; but 

 the lichens come to stay until displaced by other and 

 more important members of the family, for they are the 



