242 THE ENTOMOLOGIST. 



but numerous departures from their normal habits have been 

 observed. One or two species frequently construct nests 

 under stones, in crevices of rocks, and in other situations 

 adapted to their purpose ; others avail themselves of the 

 nests of birds; and 1 have observed one instance in which 

 Bombus senilis had taken possession of the nest of a field- 

 mouse, and I am inclined to believe this to be a not unfre- 

 quent occunence. T have recorded one instance of Bombus 

 Pratorum having taken possession of the nest of a robin, 

 built in the porch of the cottage of my friend Dr. Bell at 

 Putney ; and Bombus Muscorum was observed entering the 

 nest of a wren at liolmbush, near Brighton : the eggs of the 

 wren were embedded among the waxen cells of the bee. A 

 lady of my acquaintance, some years ago, observed Bombus 

 Muscorum collecting horsehair in the latticed window of a 

 stable, and, by watching her when conveying a load, dis- 

 covered the nest, composed entirely of that material. These 

 are a few instances sufficient to show that these bees, like 

 those of other genera, as I shall have occasion to record, 

 sometimes depart widely from the normal habit of their 

 species. 



Those species that build on the surface of the ground 

 have received the popular cognomen of moss-builders, a term 

 by no means appropriate, since, of the number of nests that 

 I have examined, not more than one in a dozen has been 

 constructed of that material. As well as my experience 

 enables me to judge, the Bombus Derhamellus more fre- 

 quently selects moss than any other species : this bee very 

 frequently selects some cavity in a hedgerow-bank where 

 moss is growing, and under such circumstances chooses that 

 material ; but in Yorkshire, where the species is much more 

 numerous than in the South, its nests are of very frequent 

 occurrence in hay fields, and in such situations they are 

 principally constructed of blades of grass and small leaves of 

 various plants, &c. The nests of Bombus Sylvarum are also 

 usually composed of grass and the fibres of plants. 



The name caider-bees has also been applied to the surface- 

 builders : they are said to comb or card the moss used in 

 constructing their nests. A very interesting account of their 

 proceedings is given by Reaumur ; Kiiby has given the 

 same history of them, and Shuckard has repeated the account 



