Habits of Megachile Centuncularis. 3 
and very frequently not more than thirty seconds ; although, as T 
afterwards discovered the rose-bush from which, from the direc- 
tion of her flight, she seemed to have cut the leaves, she must 
have flown at least a quarter of a furlong and back again, besides 
having to cut her material of its proper shape. Now if we allow 
only one-third of the whole time to have been employed in cutting 
the leaf, which certainly is less than that usually occupied in this 
labour, her velocity of flight could never have been less than at 
the rate of a mile in six or seven minutes, and often in less than 
three minutes and fifty seconds. 
At three o’clock in the afternoon her labour was completed. 
She had then closed the entrance to the nest, and had also filled 
up part of the hole with rose-leaves. After taking a survey of 
the spot she flew away, but in a few seconds returned, as if to 
press down the leaves a little closer, and then deliberately left the 
place, and proceeded in search of another hole in the same wall 
for a repetition of her labours. I then secured this interesting 
little creature as an acceptable specimen for my cabinet. 
On the 17th of July, twenty-seven days from the completion of 
the nest, I removed the bricks from the wall for the purpose of 
examining it. On separating two bricks, between which the nest 
was built, I found that the hole extended in a horizontal direction 
about five inches, and that it contained four centuncules, each of 
which was occupied by a full grown larva, that was spinning a 
cocoon of brown silk, preparatory to changing to a nymph. But 
what now excited my admiration was the instinct exhibited by the 
parent in the construction of her nest. The base of the hole 
being full of cavities, and altogether uneven, the little architect 
had remedied these defects by filling them with the cotton she had 
been so actively conveying to the spot, until the interior of the 
hole presented an even surface, around which she then placed the 
rose-leaves, the materials usually employed by her. I could not 
help feeling that this was one of those admirable variations of 
instinct which ought to make us hesitate when we are told that 
insects, and the higher orders of invertebrated animals, are not 
endowed with faculties which approach somewhat closely to that 
of reason. 
B2 
