and if its magnitude and harmonious colouring liave invited 

 the skilful hand of the artist, its singular economy and remark- 

 able structure have no less attracted the attention of the phi- 

 losopher : the learned De Geer and celebrated Lyonnet have 

 been eminently successful in their investigations of the struc- 

 ture of the caterpillars ; and their dissections and descriptions 

 being so ample and numerous, that it is in vain for me to 

 attempt here to give any satisfactory account of them, I must 

 refer the reader to those authors for the history of this extra- 

 ordinary insect, observing that the plates that illusti'ate the 

 work of the latter are amongst the most beautiful the graver 

 ever produced, and that in the delineation of the insect our 

 own countryman Harris has employed his pencil with the 

 greatest success. 



The imago of Cossus ligniperda is very inconstant in colour 

 and markings, as a comparison of the beautiful variety of the 

 female figured from Mr. Stephens's cabinet with those usually 

 taken Avill prove. Tliis variety was probably bred from a cater- 

 pillar that fed upon the oak, its usual food being the internal 

 substance of poplars and willows, which 1 have known so com- 

 pletely pierced in every direction by these larvae, which exist 

 in that state three years, that the first high wind has broken 

 them down : in other instances they have ascended the stand- 

 ards of young willow-trees, the pith of which has been entirely 

 destroyed, and of course the destruction of the stem followed. 

 They are met with occasionally in May, but most frequently 

 in September, at which time the specimen figured was found. 

 It spun up in a few days, after endeavouring to make its escape 

 from the smooth vessel in which it was at first confined, by 

 the ingenious method exhibited in the plate, forming a ladder 

 of its web which enabled it to ascend even glass to any height : 

 my attention was first called to the fact by my esteemed friend 

 Henry Browne, Esq., of Norwich, although I found afterwards 

 that it had been observed by Roesel. The caterpillars emit a 

 most disagreeable scent ; nevertheless it was the opinion of 

 Ray and Linneus that they were a favourite dish of the 

 Romans. 



The perfect insects may be taken the end of June and July 

 resting upon the trunks of those trees in which they have been 

 perfected, and upon the bark of which the females deposit their 



CSL'S. 



