318 Plumules or Battledore Scales [^Sml^^SZ'^ttm.^ 
former? and why suppose any necessity for derivation at all? 
Butterflies are often confined to narrow localities ; and when species 
are widely spread in various geographical hahitats, varieties occur ; 
but the species continue recognizable, and the more specimens can 
be obtained the more certain is their determination. It is much 
more probable and philosophical to suppose that an intelligent 
Creator placed His creatures in such localities and conditions as 
suited their various requirements, and maintained them there ; and, 
as Mr. Bates says, " a proof of this perfect adaptation is shown by 
the swarming abundance of the species." 
This swarming abundance and teeming variety of life in the 
Amazons region is not confined to the insect tribe ; for " Professor 
Agassiz, who has lately been engaged in examining the fish of that 
river, states that he has not found one fish in common with those 
of any other freshwater basin ; that different parts of the Amazons 
have fishes peculiar to themselves ; that a pool of only a few hun- 
dred square yards showed 200 kinds of fish (which is as many as 
the entire Mississippi can boast) ; and that in the Amazons itself 
2000 different kinds exist.'^ * 
We must look in vain for specific distinction, if such different 
insects as Heliconia, Melpomene, and Thelxiope are to be regarded 
as of one common origin. Mr. Bates admits that " both are good 
and true species, in all the essential characters of species ; for they 
do not pair together when existing side by side, nor is there any 
appearance of reversion to an original common form under the same 
circumstances." 
Family YI. Acr^id^. — No plumules found. 
Family YII. Nymphalid^. — Found in the following genera : — 
Eueides. — Here on five species they have been detected, and 
they bear a very strong similarity to those of the Helieonidse, the 
insects themselves being also alike. A comparison of Heliconia 
Vesta and Eueides Thales would induce a casual observer to regard 
them as almost identical; but Mr. Hewitsonf has pointed out "a 
difference in the position of the discoidal nervures of the posterior 
wing, as well as in the orange rays which proceed from the base of 
the posterior wing ; " and he well says, " If a butterfly or a genus 
resemble another (though placed systematically at a distance from 
it), let it be in colour or in form, it may be expected to resemble it 
in other characteristics." The plumule of Eueides Thales you will 
see on Plate XXXIV., Fig. 5. 
Colsenis. — Found in five species, one of the forms being shovm 
on Plate XXXIY., Fig. 6. 
Agraulis. — Found in three species, introducing a very distinct 
type, which we shall see is, as it were, played upon and repeated 
with variations in other genera (Plate XXX Y., Fig. 7). 
Terinos. — On the two species of this genus which I possess 
* ' Atbenseum,' March 23, 1867. f ' Journ. of Ent.,' vol. i., p. 156. 
