( xxxix ) 



maintains that the Bates-Muller hypotheses are seriously 

 undermined by the fact that the wings of insects were, as 

 early as the Carboniferous period, striped or barred and 

 spotted long before birds ever appealed." I cannot however 

 see that this affects the Bates-Mliller hypotheses at all. Such 

 stripes, bars and spots may for all we know, have been 

 cryptic or epigamic, but this would not preclude the ultimate 

 development either of sematic or pseudosematic coloration. 



It will be as well here to recall the fact that Professor 

 Packard entirely misunderstood what is generally known as 

 " Muller's hypothesis." Put very shortly, Miiller's suggestion 

 was that butterflies belonging to different genera, both dis- 

 tasteful, might come to resemble one another so that the 

 general sacrifice to the inexperience of insectivorous enemies 

 would ba divided between them. 



This theory was published in 1879. Nine years previously 

 Miiller had made a tentative suggestion that the resemblance 

 between protected genera had been brought about by sexual 

 selection. It is this theory which Darwin described as 

 " rather too speculative to be introduced into my book," and it 

 is also the theory which Professor Packard regarded as the 

 accepted Mullerian hypothesis. The error has been very fully 

 pointed out by Professor Meldola in a letter to "Nature" 

 published in November 1905, and materially affects the value 

 of Professor Packard's criticisms. 



Mr. Abbot H. Thayer's view that the colours of animals are 

 such as to cause the creature to cease to appear at all, appears 

 to be merely a universal application of the theory of cryptic 

 coloration. Instances of cryptic coloration are too common to 

 admit of any doubt whatever, but to maintain that every 

 animal is coloured for concealment appears to me to be too 

 much of a generalization. Probably few would deny that 

 warning colours are exhibited by many stinging insects, dis- 

 tasteful caterpillars and other offensive creatures, to take only 

 the insects alone. Mammals and reptiles, however, are also 

 known to exhibit warning colours, as for instance the skunk with 

 its white tail, the coral snake, and certain brightly coloured 

 frogs described in Mr. Belt's "Naturalist in Nicaragua." 

 The warning colours exhibited by certain caterpillars have 



