For reasons which will be easily apparent to the reader, I have reprinted the chapter called Instinct and Discernment, which was included in Bramble-bees and Others, and that on the Volucella, which, under the title of The Bumble-bee Fly, formed part of The Life of the Fly. Apart from the two chapters named and the essay on the Eumenes, which figures in The Wonders of Instinct, published in America by the Century Co., [[vi]]none of the contents of this volume has until now appeared in the English language. The Volucella is included by arrangement with Mr. Fisher Unwin, the publisher of The Wonders of Instinct in England.
My thanks are due to the late Miss Frances Rodwell and to my friend Bernard Miall, both of whom have been of great assistance to me in preparing my translation.
Alexander Teixeira de Mattos.
CHELSEA, 18 April, 1919. [[vii]]
THE MASON-WASPS
[[1]]
CHAPTER I
THE EUMENES
A wasp-like garb of black and yellow; a slender, graceful figure; wings that are not spread flat when resting, but are folded lengthwise in two; the abdomen a sort of chemist’s retort, swelling into a gourd and fastened to the thorax by a long neck which first distends into a pear and then shrinks to a thread; a leisurely and silent flight; lonely habits. There we have a summary sketch of the Eumenes. My part of the country possesses two species: the larger E. Amadei, Lep., measures nearly an inch in length; the other, E. pomiformis, Fabr.,[1] is a reduction of the first to half the scale.