PKOTECT1VE MD11CKY. 2 



belonging to the genus <Ttfmnaliu, which imitates, as many 

 Sesiidaa do, a humble boe. The only objection to regarding 

 this as a question of mimicry is the rather important one, that 

 no humble bees exist where the moth does. Dr. Seitz, how- 

 ever, suggests, not, as Mr. Scudder has, that the mimicked 

 form did exist, but has died out ; but that the moth has mi- 

 grated from some country where humble bees are found. The 

 suggestion is, however, and naturally, put forward very doubt- 

 fully. There is clearly no a priori objection to it, particularly if 

 the larva feeds in the interior of stems which are constantly 

 imported and exported, but it must as clearly remain a 

 suggestion for the present an alternative suggestion to the 

 hypothesis that the mimicked form has died out. 



Cases of Apparently Useless Mimicry. 



I am indebted to Dr. David Sharp, F.ll.S., for a curious 

 instance of resemblance between two British beetles, which 

 appears at first sight to conform to all the conditions of true 

 mimicry. 



Coeliorfes didymus is a minute beetle, very common upon 

 nettles ; with it is occasionally found a rare species, Ceutfio- 

 rhynchus itrticce ; these two insects are so much alike, that it 

 needs a careful investigation to distinguish them. And yet, 

 what advantage is got by this resemblance ? Supposing that 

 the common species is nauseous in taste, it cannot well possess 

 any other adequate defence, and this has not been proved, its 

 very minuteness would seem to render any detailed mimicry 

 more than necessary ; and yet this exists. 



A Swedish naturalist, Dr. Carl Bovallius, has lately de- 

 scribed * a remarkable species of amphipod crustacean which 



* Not: a Acta Refj. Sue. Ursula, 1885. 



