HABITATIONS OF INSECTS. 451 



T. LtOti of De Geer^, which inhabits the blossoms of 

 Lotus corniculatus ; and one which I have myself ob- 

 served to render the flowers of Erysiinum Barbarea like 

 a hop blossom. A similar monstrous appearance is com- 

 municated to the flowers of Teucrium siqrinum by a little 

 field-bug, Tingis Teucrii of Host'', 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 ap- 

 pellation 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 A, PhtacicE, which causes 

 the leaves of different species of Pistacia to expand into 

 red fingei'-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. Bursaricv, which with its brood inha- 

 bits angular utriculi on the leafstalk 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 entomologists have denominated mono- 

 thalamous, or consisting of only one chamber or cell ; 

 but some are polythalamous, or consisting of several. 



Having: thus described the most remarkable of the 

 habitations constructed by the parent insects for the ac- 

 commodation of their future young, 1 proceed to the 



° De Geer, vi. A2\. ^ Jacquin Collect, ii. 255, 



Reaum. iii. 427. 



2 G 2 



