Hymenoptera aculeata from Majorca and Spain. 663 
remarkable likeness to such common insects should convey 
an impression of extreme rarity and lead to a want of 
knowledge as to habits.  Asilid mimicry of this latter 
kind may be exactly paralleled by resemblances such 
as that of the Histerid Saprinus virescens to its distasteful 
Phytophagous prey, Phedon cochlearivx,—following the 
convincing interpretation offered by Mr. Horace Donis- 
thorpe (Trans. Ent. Soc. Lond., 1901, p. 354). 
The resemblance of the Volucellas for the Aculeates 
has probably been brought about in a slightly different way, 
although here too the older interpretation of the mimicry 
as aggressive must, I believe, be abandoned. My friend Dr. 
W. Hatchett Jackson has recently presented to the Hope 
Department a specimen of Volucella inanis, which he 
captured on August 29, 1903, close to the entrance of a 
wasps’ nest in his garden at Pen Wartha, Weston-super- 
Mare. The wasps paid not the slightest attention to it, 
although they instantly attacked other insects venturing 
near the opening. Considering that wasps will detect 
and kill the individuals from other communities, it is 
most improbable that they were deceived by the appearance 
of the Voluwcella, Furthermore, Dr. Jackson has had the 
opportunity of studying M. Fabre’s latest volume, and 
informs me that the great observer believes V. inanis to be 
a beneficial guest in the wasps’ nest, feeding on débris, 
waste substances, excreta, etc. He also states that the 
larvee of these diptera are not attacked even when upon 
the combs of the wasp. ‘These results entirely accord 
with observations upon V. bombylans carried out by the 
present writer in association with Miss Cora B. Sanders 
early in July 1898. Fresh and active specimens of the 
Volucella were lightly but securely girdled with a fine 
silken thread, the other end being attached to a long 
slender twig. In this way it was possible to guide the 
movements of the fly and compel it to wander close to the 
opening of the underground nest of Bombus terrestris, and 
even toenter the passage. Examples of both the red-tailed 
form of V. bombylans and the banded form (var. mystacea) 
were thus tested, and only once was any antagonism dis- 
played. On this occasion the Volwcella was made to 
descend the passage, and thus met an ascending worker. 
The humble-bee grappled with the fly, wrestled with it in 
a clumsy manner for a few seconds, and then left it 
apparently without having caused any injury. We also 
