AFRICA. 357 
the feafon, nor is it the greater or lefs propin- 
quity of the equator, that occafions a more or 
lefs abundant vegetation. The fun itfelf, elfe- 
where confidered as the primary caufe of fer- 
tility, is here the fecondary only. Its heat, it 
is true, is affifting to the birth, growth, and 
ripening of vegetables ; but they are the rains 
more particularly that occafion them to fpring 
up and unfold themfelves, that determine in 
great meafure the place and time of their ap- 
pearance, and caufe them to fhow themfelves 
in one place fooner than in another. Now as 
the rains themfelves are owing to the fituation 
of the mountains which attrad the clouds, it 
follows, that they may be very unequally dif- 
tributed, and that one fpot may be deluged 
with them, while another, properly watered, 
Ihall difplay a vigorous (late of vegetation, and 
a third, dry and parched, exhibit only the 
image of death and defolation. 
From this fortuitous occurrence of the rains, 
fome vegetables have a fort of accidental fuc- 
ceffion, according to the fpots on which they 
grow, that naturally they ought not to have. 
Thus in one place a fpecies of flower has juft 
blown, which farther on appeared fix weeks 
A a 3 before. 
