.8,,. RECENT OBSERVATIONS UPON MIMICRY. 13 



These plates were drawn by the author from a diving-bell, and 

 illustrate the prevailing green hue of the inhabitants of the sea ; 

 animals, which in other localities are very rarely green, are green 

 here ; particularly is this so with the corals. Professor Haeckel 

 admits this to be a remarkable fact. Tlie prevalence of green among 

 the inhabitants of the adjoining land is not so noteworthy a fact, since 

 it might be reasonably put down to a protective imitation of the 

 surrounding foliage ; and green is not an uncommon colour among 

 forest-dwelling animals. 



One of our handsomest English butterflies, the " Clouded Yellow " 

 {Colias edusa), has a well marked variety known as Helice, and this 

 variety chiefly differs in its paler colour. In the Argentine Republic 

 there occurs a species much like Edusa, which has also a varietal 

 form differing from it about as much as Helice does from Edusa. 

 In certain districts of the same region of America, Dr. Seitz 

 met with a common butterfly which he at first mistook for the 

 European Vanessa levana, so closely does it resemble that insect in 

 colour and marking. Furthermore, it has a varietal form which is, 

 in the same way, exceedingly like a variety of the European 

 insect. A closer examination of the American butterfly showed that 

 it belonged to a quite diff"erent genus. " If," remarks Dr. Seitz, 

 " these insects were found in our country, no one would doubt that 

 this is a case of mimicry as perfect as any which exists." 



Sir Walter Buller, in his work upon New Zealand birds, has 

 commented upon the extraordinary likeness which a cuckoo of the 

 genus Eudynamis bears to a hawk. This fact is not new, for other 

 cuckoos are like hawks ; our own cuckoo is so much so that there is 

 even a legend to the effect that in the winter it becomes a hawk. The 

 interesting point about this particular cuckoo is that it " mimics," not 

 a New Zealand, but a North American, hawk. This last instance 

 may be fairly regarded as purely accidental ; but with regard to the 

 butterflies, we cannot but suppose that similarity in the conditions of 

 life is responsible for their mutual resemblances. This phrase is 

 doubtless vague and unsatisfactory, for at present we have not 

 sufficient knowledge to fornmlate a more accurate statement. 



It has been already pointed out that evidence is in many cases 

 wanting of the advantages which an insect gets by mimicking 

 another ; the "Bee Hawk Moth " is an example of what might, in an 

 oft-quoted phrase, be called "a palpably intentional likeness that is 

 perfectly staggering " ; even a naturalist of experience might be 

 excused for putting it down as belonging to the Bee tribe. And yet 

 Mr. Poulton found that it was eaten " without hesitation or caution " 

 by a lizard. Dr. Seitz^ noticed in South America a kind of 

 " Humming-bird Hawk Moth " which closely mimicked a particular 

 species of humming-bird found in the same locality. The resem- 



1 Stettiner Entom. Zeitschr., 1890. 



