1876. ] Mimicry in Butterflies. 585 
Farther on he asserts that “ the acceptation, as the starting- 
point in the origin of mimicry by natural selection, of a resem- 
blance having its beginning at such a distance can scarcely be 
shaken by a single known case. It should, moreover, not escape 
attention that the sharp-sightedness of enemies is itself also a 
quality at first gradually acquired in the struggle for existence, 
and one which must increase, from the very fact that by protect- 
ive coloring, mimicry, etc., the persecuted species escapes the less 
sharp-sighted pursuer. This ever-increasing sensitiveness and 
Sharp-sightedness of the pursuer on the one hand explains the 
wonderful completeness of many natural imitations, and on the 
other makes the acceptation of an originally very slight resem- 
blance the less hazardous.” 
Fritz Müller insists, as all writers on the subject have done, 
upon the similar geographical distribution of the imitating and 
the imitated species as a necessary concomitant of mimicry; but 
instead of believing with other authors that the Leptalids have 
become poor flyers in their imitation of the feeble-winged 
lthomia, he holds that the wretched powers of flight possessed 
by the species of Leptalis have been the very cause of mimicry ; 
the insects needed mimicry the more the poorer flyers they were. 
Mimicking species of course stand between their original type 
and the mimicked species; and since mimicry is often confined to 
the female, we should expect in such cases to find the following 
Series: original form, male of mimetic species, female of same, 
species mimicked. 
In his vicinity, Miiller has found five species of Leptalis, of 
Which only four are common, and are discussed by him. Of these 
four, Lept. Melia mimics nothing ; all the other three are imita- 
tive species and mimic distinct groups of butterflies; Lept. Asty- 
nome resembling a Heliconian-like Danaid, Mechanitis Lysimma ; 
another, which he calls Lept. Thalia, mimicking an Acræan, 
Acrea Thalia so closely, that Müller at first supposed it to be an 
Acræan ; and the last, Lept. Melite, bearing a close resemblance 
to the female of one of its own family, Daptonoura Lysimnia. 
A comparison of the form of the wings of these different in- 
shear shows the following series : — o , 
MD Pieris or Daptonoura, Mechanitis Lysimnia, Leptalis 
“ynome 9, Leptalis Astynome 4, Leptalis Melia. _ 
2.) Pieris or Daptonoura, Acræa Thalia, Leptalis Melia. 
l B.) Pieris or Daptonoura, Leptalis Melite ¢, Leptalis Me- 
_ we 3, Leptalis Melia. 
