09-2 HABITATIONS OF INSECTS. 



found undergoing its transformations in the stems of the hollyhock^, that 

 all the species of this genus do not pass their larva state in the interior of 

 seeds as most of them do. Other galls owe their origin to moths, as those 

 resembling a nutmeg which Reaumur received from Cyprus-; and others 

 again to two-winged flies, as the woody galls of the thistle caused by 

 Tnjpcta CarduP, and the cottony galls found on ground ivy, wild thyme, 

 &,c., as well as a very singular one on the juniper resembling a flower, 

 described by De Geer"*, all which are the work of minute gall-gnats 

 (^CecidomyicB Latr.). Some of these last convert even the flowers of 

 plants into a kind of galls, as T. Loii of De Geer^, which inhabits the 

 blossoms of Lotus corniculatus ; and one which I have myself observed 

 to render the flowers o( Eri/simum Barharea like a hop blossom. A similar 

 monstrous appearance is communicated to the flowers of Teiicriwn supimim 

 by a little field-bug, Tingis Teucrii of Hosl^', and to another plant of the 

 same genus by one of the same tribe described by Reaumur.'^ In these 

 two last instances, however, the habitations do not seem strictly entitled 

 to the appellation of galls, as they originate not from the egg, but from the 

 larva, which, in the operation of extracting the sap, in some way imparts 

 a morbid action to the juices, causing the flower to expand unnaturally ; 

 and the same remark is applicable to the gall-like swellings formed by 

 many Aphides, as ^. Pistacice, which causes the leaves of different species 

 of Fistacia, to expand into red finger-like cavities ; A. Abietis, which 

 converts the buds or young shoots of the fir into a very beautiful gall, 

 somewhat resembling a fir-cone, or a pine-apple in miniature ; and A. 

 Bursarice, which with its brood inhabits angular utriculi on the leaf-stalk of 

 the black poplar, numbers of which I have observed on those trees by the 

 road-side from Hull to Cottingham. The majority of galls are what ento- 

 mologists have denominated nionothalamous, or consisting of only one 

 chamber or cell ; but some are polythalamous, or consisting of several. 



Among the more remarkable galls are those so much resembling minute 

 fungi as to have been actually described as such ; as Sderothnn fasciculatum 

 Schumacher, which is a common gall on oak leaves; and the Rev. INI. J. 

 Berkeley has given an account of a similar one found by W. S. MacLeay, 

 Esq., in Cuba, on the leaf of a plant of the order Ochnacecr, which on a 

 cursory examination was regarded by some of our first botanists as an 

 epiphytous fungus, but proved on dissection to be a true gall, and distin- 

 guished from all previously known by its very curious operculum or lid, 

 evidently meant for the more ready egress of the' occupant (which has not 

 yet been ascertained) in its perfect state.^ 



Having thus described the most remarkable of the habitations constructed 

 by the parent insects for the accommodation of their future young, I proceed 

 to the second kind mentioned ; namely, those which are formed by the 

 insect itself for its own use. These may be again subdivided into such 

 as are the work of the insects in their larva state ; and such as are formed 

 by perfect insects. 



Many larvae of all orders need no other habitations than the holes which 

 they form in seeking for, or eating, the substances upon which they feed. 



» Weslwood, iihi supra, i. 337. * Reanm. iii. 448. ' Ihid. 455. 



* De Gccr, vi. lO'.i. * De Geer, vi. 121. • Jacquin Collect, ii. 255. 



^ Reaum. iii. 427. * Trans. Linn. Soc. xviii. 576. 



