i68 
NATURE STUDY. 
ferns in a tropical forest and the enormous size to which 
many of them grow is very quickly disabused of any such 
a notion.” Also in speaking of the abundance of these 
ferns even in temperate regions, he says, “Occasionally a 
single species of fern, e. g. Pteris aquidina, (common brake) 
covers large tracts of ground almost to the ex¬ 
clusion of other vegetation.” These last seven 
words, “almost to the exclusion of other vegeta¬ 
tion,” are particularly significant as indicating 
the success which has attended specialization. 
Not only are these plants able to thrive passive¬ 
ly in favorable conditions; they are able even to 
maintain a contest with plants of a higher organ¬ 
ization and literally drive them from the field. 
These facts, together with evidences gathered 
from the geological records, go to prove this 
great family, instead of being a “left over” type, 
is essentially a modern one. The ability to 
maintain 70 genera and 3000 species under mod¬ 
ern conditions of life on our globe is of itself 
sufficient proof of enormous vitality and of won¬ 
derful adaptability. And to the observer who 
knows the ferns at all, a walk anywhere along 
country roads in summer will bring conviction 
of the truth of these statements. With the sin- 
J f gle exception of the osmundas, and possibly one 
grape-fern, all the ferns he sees are of this fam¬ 
ily and they are scattered broadcast, in field, 
meadow, glen, wood, swamp and bog, on cliff 
Fig. 2. and in ravine, and at all elevations, from the sea 
to the mountains. 
New England possesses a good representation of this 
family, having 13 genera and 40 species. The following 
are the names of the genera and the number of species in 
each: Onoclea, 2 ; Woodsia, 4; Dicksonia, 1 ; Cystopteris. 
