78 THE ENTOMOLOGIST. 



parasitic. Some instances may undoubtedly be advanced, as Apatlius 

 and Bombus, and also in the different species of Volucella, which 

 infest the nests of humble-bees ; but amongst the solitary bees no 

 such resemblance is required to aid in any necessary deception." — 

 P. 'H'i. * ■•' =:= " I have on several occasions watched with much 

 enjoyment a large colony of Eucera longicornis, the males occasionally 

 darting forwards with great velocity, then turning sharply round, and, 

 as it were, swimming in circles close to the ground, then darting off 

 again and again in an unceasing round of sportive enjoyment; their 

 industrious partners, whose whole existence appears to be bound up 

 in one unceasing round of labour, would occasionally return home 

 laden with food for their young progeny. Sometimes it would happen 

 that a Nomada had previously entered her nest. When such proved 

 to be the case she would issue from it, and flying off to a short 

 distance wait patiently until the parasite came forth, when she would 

 re-enter and deposit her burden." — P. 22. 



The author very justly says, "If 1 were asked which 

 genus of bees would afford most abundant and interesting 

 materials for an essay on diversity of instinct, I should, without 

 hesitation, point out the genus Osmia.^^ His introductory re- 

 marks to this genus do indeed form such an essay. From it we 

 cannot do better than quote the following, as a curious example 

 of delayed development under certain circumstances: — 



" There is another species of this genus, whose habits are so 

 different from the rest that our admiration of the ingenuity of these 

 bees is greatly increased when we consider its curious details, and 

 reflect upon the degree of care and foresight exhibited by the 

 provident parent ; this is the Osmia parietina, a bee only as yet 

 found in the northern parts of this country. This species selects the 

 under side of a slate or stone lying on the ground, and having a 

 hollow space beneath ; to the under side of such stone the bee 

 attaches little masses of pollen and honey ; on each she deposits an 

 egg, from which a larva is hatched in a few days, which feeds upon 

 the provision stored for it by its provident parent. A stone of this 

 kind was found in 1849 at Glen Almond, Perthshire, on the 

 Grampians, at an elevation of eight hundred feet above the level of 

 the sea, by Mr. J. Pobertson, who, on turning up the stone, 

 observed a mass of cocoons of some insect. Although not ^^ossessing 

 much knowledge of Entomology, still he knew them to be the 

 production of some insect. He presented the stone to the British 

 Museum, and it was placed in my hands for observation. The size 

 of the slab was ten inches by six, and the number of cocoons attached 

 to it two hundred and thirty. When first discovered about one-third 

 of them were empty : this was in the month of- November. In the 

 beginning of the following March (1850) a few males made their 



