xii THE HUMBLE-BEE 



FIG. PAGE 



19. Vertical section through a domicile in Sladen's humble- 



bee house . . . . . . . .95 



20. The sections or storeys shown separately ... 96 



21. Comb of B. terrestris from Sladen's humble-bee house . 101 



22. Section of Sladen's original device to attract underground- 



nesting humble-bees . . . . . .105 



23. Sladen's domicile for humble-bees, with Sladen's wooden 



cover . . . . . . . . .109 



24. Vertical section of Sladen's tin domicile . . . .113 



25. External anatomy of B. ruderatus . . . . .145 



26. Hind metatarsus of B. terrestris (male), B. lucorum (male), 



B. soroensis (male), and B. pratorum (male) . . 163 



27. Queen of B. latreillellus incubating her immense lump of 



brood . . . . . . . . . ' 185 



28. Diagram of cocoons in a commencing nest of B. der- 



hamellus . . . . . . . .190 



29. Hind-leg of Bombus and Psithyrus female . . . 203 



30. Tip of abdomen (under-side) of the queens of each of the 



British species of Psithyrus, showing the elevations on 



the 6th ventral segment ...... 204 



3 1 . Antennae of Ps. vestalis $ and Ps. distinctus $ . .211 



32. Device for excluding ants from humble-bee's nest . . 229 



t,2- How to hold a humble-bee . . . . . .266 



34. Loads of pollen collected by Bombi . . . .274 



PLATES 



I. Bombus terrestris queen, worker, and male. To face p. 158 

 ,, lucorum ,, ,, 



,, lapidarius ,, 



,, soroensis ,, ,, 



II. Bombus pratorum queen, worker, and male. To face p. 172 

 ,, lapponicus ,, 



,, joncllus ,, ,, 



cullumanus male {slightly faded). 

 ,, ruderatus two dark males, three dark queens. 



