Retrospective Criticism, 49 1 



more ready to believe this statement, from having so repeatedly observed 

 the great partiality of the insect, in the fly state, for these two evergreens.* 

 I might add, too, as a corroborating circumstance, that the insect, as I have 

 remarked (Vol. IV. p. 477.) is more than usually plentiful in this neigh- 

 bourhood, where the holly and ivy naturally abound, and especially about 

 my own premises, on which there are many fine specimens of each tree, 

 particularly of the ivy. Your correspondent, Mr. Ventris (p. 205.), is 

 inclined to think the caterpillar of our little azure blue, like its congeners, 

 feeds on grass, as stated by many entomological writers. I wish some one 

 would institute such experiments as would enable one to ascertain the 

 point without doubt, and communicate the result through your Magazine. 

 The caterpillars, I believe, of most, if not all, of the blues, feed upon 

 grass, or upon the various herbage of which turf is composed in different 

 parts of the country : and though they must be, in some cases, exceed- 

 ingly abundant, they are yet very rarely met with, owing, probably, to their 

 feeding very near the surface of the ground; or, possibly, like some other 

 caterpillars, coming forth to feed only, or chiefly, by night. P. Argiolu^, in 

 the winged state, appears to differ widely in its habits and manners from all 

 its congeners (I speak only of such British species as I am acquainted 

 with) : they are mostly to be met with on commons, open pastures, downs, 

 chalk hills -j-, &c. They fly low, and frequently settle on the flowers, grass, 

 and other herbage, occurring in such situations. P. Argiolus, on the con- 

 trary, rather affects hedges, gardens, shrubberies, and plantations, and is a 

 more restless and high-flying insect, hovering and vapouring '\. about the 

 trees and bushes. Nor have I observed that it evinces the same partiality 

 for settling upon flowers and plants of humble growth, as it does for set- 

 tling on the leaves of the holly, &c. : I say the leaves^ for the blossoms are 

 not out till after the season for the sprhig brood, at least, of the butterfly, is 

 gone by, or nearly so. Since this insect, therefore, differs in the winged 

 state so widely in habit from its congeners, it is not improbable that it may 

 likewise do the same in the larva. But (as already stated) I hope some 

 one will, ere long, be able to settle the question beyond dispute. Yours, 

 &c. — W. T. Bree. Allesley Rectory, March 8. 1832. 



Irritability of the Hairs of the Round-leaved Sundew (Drosera rotundifolia'), 

 — Has not J. E. L. imputed to the sundew a property of which it is 

 totally destitute? He remarks (Vol. IV. p. 135.): — " Drosera, an Eng- 

 lish genus, which inhabits our marshes, has its leaves clothed with beau- 

 tiful long scarlet hairs ; and if a fly happens to alight upon any of the 

 leaves, these hairs immediately curl over it, and squeeze it to death. Per- 

 haps these hairs may be provided by Providence, in order to catch flies and 

 other insects, from which the plant might obtain nourishment." The hairs 

 of the English Droserae, or sundews, have surely no such degree of irrita- 

 bility, and, I believe, none at all. The fringed laminae of the leaves of the 

 Dionae^fl! Muscipula, or Venus's flytrap, a native of Carolina, have this 

 power ; and, for aught I know, this plant alone. The fly-catching powers 

 of the Droserae, or sundews (and these are quite inconsiderable), consist, I 

 believe, solely in the viscosity of the leaves and hairs. The idea of the 



thorn (^hamnus Frangula) and holly ( JTlex europae^a [^quifolium ?]. See 

 Haustelliita, vol. i. p. 85. 



* The butterfly is also fond of settling on the Portugal laurel, rhodo- 

 dendron, and other evergreens. 



f Hence, probably, it is, that such pastoral names as Corydow, Addni*, 

 Alsm, Alexia, have been elegantly appropriated, as specific appellations, to 

 several species of this family of Papilionidae. 



X Were an appropriate English name required for this little buttei'fly, it 

 might well be called the " vapouring blue." 



