CLOTHED WITH VEGETATION: 6l 



They suck up the minerals of the soil to make stalks 

 and fronds which die annually to enrich the soil for other 

 plants. The roots live on for many years, transforming in 

 this way the soil for a better vegetation. Since the small 

 overtures of the first days, the continuous toil of the ferns 

 has been so great that the many tons of earth transformed 

 would be hard to calculate. 



All of these lower orders of plant life are propagated by 

 spores, and it is easy to see how the winds would carry 

 them each year a little farther towards the face of the re- 

 treating ice sheet. Other plants of a higher order cast 

 forth their seeds doubtless, upon the winds : but it is 

 obvious that the lower kinds of plants would earlier get a 

 footing in the cold new soil, because they were less fastidi- 

 ous about their climate and their food. The seeds of 

 grasses, for example, might have started northward at every 

 fresh breeze of summer, but many thousands of them 

 would rot in the cold moisture where the spores of the alga 

 and lichen and moss and fern would be happy. 



Yet all of these low-grade plants, mean as the circum- 

 stances are which they find endurable, thrive better when 

 accompanied by the nobler kinds of vegetation. The 

 fungus, for example, although next in order to the lichen, 

 needs a rich deposit of vegetable mould, the corpses 

 of a million generations of other plants, upon which to 

 thrive. 



The puffball is one which grows now in Cohasset to an 

 enormous size, two having been found in the year 1896 which 

 measured thirty-three inches in circumference. It is ob- 

 vious that the early post-glacial times could not furnish so 

 good conditions for the growth of this great fungus {Lyco- 

 perdou giganteujn). The funguses need such things as 

 decaying trees or leaves to grow upon, and therefore 

 they could not colonize in Cohasset until thick woods of 

 long standing had been made. 



But how did the woods come .'' 



