440 NATURAL “SCIENGE, JuNE, 
Larve of C. verbasci were taken feeding exposed on the upper 
side of leaves of mullein; they were green, yellow, and black, very 
conspicuous, and not hairy. One was offered to the jackdaw when the 
bird was very hungry; it was refused at first, then tasted once only, and 
dropped with greater signs of disgust than in the caseof D. caeruleocephala. 
After this he would not take anything at all from me for a considerable 
time, and appeared very uncomfortable. 
In the case of Acvonycta pst and Bombyx rubi the animals ex- 
perimented on were three slowworms (Anguis fragilis) and one lizard 
(Zootoca vivipara). These were purposely kept very hungry, but though 
the larve were left with them for three days they refused them 
entirely, never even attempting to taste them. Both these larve, 
however, were hairy as well as conspicuous, and, therefore—assuming 
that conspicuousness means unpalatability—were doubly protected. 
The fact that an animal may possess more than one kind of protection 
must of course be taken into account in making these experiments, 
and for this reason the experiments with D. caevuleocephala and C.verbasct 
were the most satisfactory, because here the unpleasant’ attitude was 
almost certainly taste only. Mr. Poulton says (Proc. Zool. Soc. Lond., 
March 1, 1887) that Mr. Jenner Weir found the two last-named 
larve to be disregarded both by birds and lizards. This certainly 
supports Professor Wallace’s original suggestion of the unpalatability 
of conspicuous larve to ‘some, at least, of their enemies,” while, on 
the other hand, the results obtained by mealso favoured Mr. Poulton’s 
suggestion as to hunger putting a limit to this method of defence, 
since the larve were tasted, and tasting would be as fatal to them as 
eating. 
Mr. Beddard (“* Animal Colouration,” p. 164) found that A. psi 
was eaten by Lacerta viridis, and at least tasted by a thrush, but he 
does not mention whether either was hungry on these occasions, a 
point of some importance. In any case, his results differed from 
mine in this experiment, but then a different species of lizard was 
used. L.vividis would seem, from other experiments of Mr. Beddard’s, 
to be less sensitive to unpleasant attributes than other lizards, 
Z. vivipara, for instance. This difference of behaviour does, as Mr. 
Beddard points out (Joc. cit., p. 155), show that unpalatable animals 
with warning colours are not always exempt from attack, but this 
very fact rather tends to support the view held by Mr. Poulton that this 
means of defence can only safely be adopted by a limited number. On 
the other hand, it militates strongly against Dr. Eirig’s theory, quoted 
by Mr. Beddard, that brilliant colours (¢.e., abundant secretion of pig- 
ment) are the cause of inedibility. Exceptional cases like that of 
L. viridis eating Acronycta psi are difficult to explain on this hypothesis, 
but they appear more comprehensible on the theory of limitation. 
A. psi might be regarded as one of the few examples of the failure as 
a means of defence both of the unpleasant attribute and its adver- 
tising warning colours, and L. viridis as having had its power of 
