AFRICA. 359 
our knowledge, and Increafe the treafures of 
natural hiftory. What then would be efFeded, 
fliould a man of information repair to fome 
fertile and more diftant fpot, and remain a 
whole year, fo as to fee all that nature produces 
there blow in fucceffion under his eye ! 
What I have faid concerning plants is with 
equal truth applicable to birds ; for the influ- 
ence of the rains, which accelerates or retards 
the unfolding of the former, cannot fail to 
occafion great difference in the laying, incuba- 
tion, and moulting of the latter. 
That I may render a double fervice to per- 
fons attempting a fimilar enterprife to mine, I 
fliall infert here a remark, which I confider as 
important, and that may fave them from many 
mifiakes ; which is, that the variation which 
is obferved to take place in the fame fpecies of 
plants, according to the difference of age, of 
time, and of place, takes place alfo among 
the feathered tribe. 
This accidental and tranfitory dlfTmiilitude 
is fometimes fo great, that a perfon would 
fuppofe himfelf to fee individuals totally diffe- 
rent ; and I have known men learned in books 
and fyflems as much deceived in this refpeft as 
A a 4 others. 
