PREFACE. 



I published in 1852 my Monograph on the Solitary Wasps; 1 

 which forms the first volume of my Studies on the Family of the 

 Vespidse. 2 As soon as that work was printed, I perceived that 

 it was ve*y imperfect. 



I was still a mere student when I composed the greater part 

 of this book ; it bears too evident marks of its premature publi- 

 cation. I consequently felt the necessity of correcting and com- 

 pleting it by means of a Supplement which occupies the greater 

 part of the third volume of the Studies on the Family of the 

 Vespidse. This, however, was insufficient. 



To the imperfections in the MS. of the work, attributable to my 

 inexperience, were added those of the form. I had the misfortune 

 to fall into the hands of a printer who not only delayed for years 

 the publication of the work, but who also executed it in a shame- 

 ful manner, neglecting to make proof corrections, and printing 

 the notes in the midst of the text. 



Having lost all patience with the delay and errors of the work, 

 I turned my back on the social wasps and started for America, 

 leaving to the care of my excellent and worthy friend, Dr. Siebel, 

 who had often aided me with his skill and advice, the task of 

 superintending the impression. Two years after, on my return 

 to Europe, I found that only three or four sheets had been printed, 

 and that the third volume was only on the eve of being finished, 

 and it was not until 1857 and 1858 that the volume on the social 

 wasps was completed, by the appearance of the general part, in 

 which were developed the facts concerning the nidification of these 

 insects, of which a summary alone had appeared in 1 853 and 1854, 

 in the explanation of the plates, and in a special pa*per. But 



1 Monographie des Gruip^s Solitaires. Geneve, Paris. 



2 Etudes sur la Famille des Vespides, 3 vols, and atlas. 



(v) 



