Butterflies of Protected Genera. 419 
knowledge should have become unerringly fixed by heredity 
in all young birds. In-the ease of the very bird in question, 
there is, in fact, direct evidence that no such instinctive know- 
ledge exists. Mr. Stainton relates (Proc. Ent. Soc. 1866, 
p- xlv) that he was in the habit of killing moths that had been 
attracted by light by the fumes of burning sulphur, and on 
one occasion, on throwing the useless specimens to a brood of 
young turkeys, “amongst a number of A. exclamationis, 
there was one specimen of Spilosoma menthastri; and though 
not one of the young turkeys rejected a single A. exclama- 
tionis, they each, in succession, took up the S. menthastri and 
put u down again, and it was left, conspicuous as it was, on 
the ground.” In the case of insectivorous foes other than 
birds there is also evidence upon record that even adult lizards 
and frogs do not know some nauseous insects till they have 
actually seized them, as has been shown by the experiments 
of A. G. Butler with the caterpillar of Abraxas grossulariata 
and the imago of Zygena filipendule (Trans. Ent. Soc. 
1869, p. 27). 
Passing from these old and now well-known experiments, I 
will give an extract from Dr. Fritz Miiller’s last letter :— 
“Jt appears to me always worth while to discuss thoroughly 
the question whether birds and other butterfly-eaters know 
eatable and uneatable species through instinct & priort, or 
whether they have to learn this through individual experi- 
ence. I hope to be able to do this shortly in ‘Kosmos.’ In 
the case of birds, I have as yet no direct proof; but in insects, 
and especially in bees, my brother Hermann Miiller and I 
have repeatedly observed that they neither know instinctively 
the flowers which serve to provide them with honey or pollen 
nor the way in which their booty is best to be obtained. T'o- 
day, for the first time, a new illustration has been furnished 
by Trigona ruficrus in visiting a Cypella which offers easily 
accessible honey and pollen, and which the majority of these 
bees nevertheless could not at first find. ‘Thus, by analogy, 
the same would occur in birds with respect to eatable insects 
as in insects with respect to flowers yielding nutriment.” 
As one piece of evidence bearing upon this subject, Dr. 
Miiller encloses in his letter a specimen of a Heliconius which 
had apparently been seized, when at rest, by some bird, as 
there is a notched piece bitten out of the two fore wings; and 
I havein my possession another specimen of Helicontus which 
is similarly notched on both hind wings. 
There is one other argument which may be adduced from 
psychology in favour of the proposed extension of the theory 
of mimicry. It is admitted by psychologists oe there is a 
