1912.] NATURAL SCIENCES OF PHILADELPHIA. 309 



Progs: 



Croesus septentrionalis, 1 A A 



Thus it appears that these experiments are inconsistent among 

 themselves, and from the fact that at least fifteen of the forty-four 

 insects alleged to have been proved distasteful by the experiments 

 are known to be eaten by wild British birds, we are justified in 

 suspecting that the experimental results do not accurately indicate 

 behavior under natural conditions. 



A fifth table by Poulton comprises the results of experiments with 

 insects which are protectively colored or which evade their enemies 

 by other means. On the theory, therefore, all of these insects should 

 be eaten freely by insectivorous animals. However, in sixteen out 

 of sixty-eight cases, more than 23 per cent., 56 the "evidences of 

 distaste" are fully as strong as in the majority of the cases in the 

 first four tables. Taking this fact in connection with that previously 

 adduced, to the effect that 17 per cent, of the " protected" insects 

 were not shown to be "unpalatable" to anything, and the additional 

 fact that sixteen out of the forty-four, or 36 per cent., were included 

 on the basis of disregard (some of them being eaten also), it is quite 

 •clear, that the insects, etc., were sorted out into the various tables, 

 in accordance with the requirements of the theory, experimental 

 evidence to the contrary notwithstanding. If authors are not 

 •consistent in the interpretation of the results of experiments, how 

 can they expect others to have faith in them? 



Poulton tries to explain the refusals of certain "protectively 

 colored" imago Lepidoptera; for instance, with regard to Vanessa 

 urticce he says (p. 246) : "I have no doubt that the refusal of some 

 frogs was due to scales only," and of Pieris brassicce, "eaten readily 

 by all lizards, but not much relished, I believe, because of the mechani- 

 cal difficulty of the scales and wings and not from being actually 

 unpalatable." We cannot accept these explanations (which no 

 doubt are true) without asking that they be made to cover the 

 refusals of all adult Lepidoptera (of proper size for the animal experi- 

 mented with). This would affect four species of Table IV and seven 

 in Table V. We find Poulton later regarding P. brassicai as intrinsi- 

 cally unpalatable (P. Z. S., 1911, pp. 864, 865). 



The inconspicuous larvae of Mania typica were tasted and rejected 

 by Lacerta muralis, Poulton's comment is: "At first sight a most 



56 This does not take into account earthworms and fly larvse, which were 

 rejected as well as refused, although the fact is not stated in the table. 



