(a xciv 2) 
regards both larve and imagos of European species, are sup- 
ported by a few made by Belt with Heliconiine in Central 
America, by D’Urban and myself with Danaine and Acreeine* 
in South-Africa, and by Haase with Danainz in Singapore. 
It is manifest, of course, that even the most distasteful 
forms cannot enjoy complete immunity from persecution; in 
ordinary circumstances they are doubtless mainly kept down 
by parasitic insects,t and during any scarcity of more pala- 
table prey it is certain that they will be devoured faute de 
mieux by vertebrates and invertebrates alike. To the latter 
condition are perhaps due such cases as Distant’s ¢ note of 
the orthopterous Hemisaga devouring. an imago of Danais 
chrysippus ; Col. Yerbury’s || observation that in Ceylon 
Euplwa core and Delias eucharis were largely taken by a Mantis, 
and Danais limniace by two kinds of Asilid~@; and Belt’s 
remark that a flower-frequenting spider captured Heliconiide. 
(p.) As regards the important point whether the protected 
forms have to suffer a certain percentage of loss from the 
attacks of young and inexperienced birds and other animals, 
it must be admitted that the evidence at present forthcoming 
is exceedingly scanty; and I have long felt considerable 
doubt as to the sufficiency of this factor to account for the 
mimetic resemblances, often remarkably close, between mem- 
bers of associated protective groups. But on reviewing care- 
fully the recorded observations which appear to bear on the 
question, I have found reason to think that there is enough 
support to justify the provisional acceptance of the Millerian 
explanation, We have in the first place Fritz Miller’s own 
capture of Heliconi and Acreine with a notched piece 
bitten out of the wings, and Distant’s (l.¢., p. 65) of a Danais 
chrysippus whose wings had been bitten unsymmetrically, — 
apparently by a bird. Then there is the significant record 
* De Nicéville (Butt. Ind., etc., i., p. 318) notes that Acrea violw was the 
only butterfly rejected by all the species of Mantide to which he offered 
various butterflies. 
+ C. V. Riley (apud Haase, l.c., ii., p. 47) found that a dipterous parasite 
was very prevalent in the larve of Danais archippus, often destroying a 
whole brood. 
{ Nat. in Transvaal, p. 65 (1889). 
|| Proc. Ent. Soc. Lond., 1897, p. xl. 
