184 A NATURALIST IN HIMALAYA 



This close resemblance between insects of different 

 orders has been observed in different parts of the 

 globe. Another instance specially struck me, though 

 it has frequently been noticed before, of the extra- 

 ordinary similarity in the external appearance of the 

 flies, Bombylius, to the humble-bees, Bombus. 



The common humble-bee in these hills was Bombus 

 tunicatus. It used to frequent the wooded slopes at 

 an altitude of 8000 feet, and there it busied itself 

 amongst the flowers that blossom above the under- 

 growth. Now the coloration of this bee is very 

 distinctive. It displays a black shining head, a thorax 

 hoary white with a black band between the wings, an 

 abdomen with three successive bars of white and black 

 and red. We look to the fly and see an identical 

 coloration : the same black head ; the same pubes- 

 cent thorax with its hoary fur and intermediate band 

 of black ; the same abdomen with its bars in the same 

 order, white and black and red. In fact the insects 

 are marked from head to tail with seven transverse 

 bands, and these bands are identical in each. Such 

 superficial resemblance is remarkable. For it is 

 evident not only in the exact shade of coloration, 

 but in the width of each band, and the general scheme 

 of decoration is identical in both. Similarly it is with 

 the shape and build of the insects and the buzzing 

 sounds that they produce. They occupy the same 

 stations and feed on the same flowers. If defence is 

 gained by this resemblance it must be all in favour of 

 the fly. And this would seem in accordance with the 

 principles of mimicry. For the fly is the more 

 defenceless of the two ; it exists in much fewer 

 numbers than the bee ; it is a more wary and active 



