256 HABITATIONS OF INSECTS. 



stopped, some in the leaves, other in the twigs, and had there hatched 

 and produced galls ! Redi's solution of the difficulty was even more ex- 

 traordinary. This philosopher, who had so triumphantly combated the 

 absurdities of spontaneous generation, fell himself into greater. Not 

 having been able to witness the deposition of eggs by the parent flies in 

 the plants that produce galls, he took it for granted that the grubs which 

 he found within them could not spring from eggs : and he was equally 

 unwilling to admit their origin from spontaneous generation, an ad- 

 mission which would have been fatal to his own most brilliant discoveries. 

 He therefore cut the knot, by supposing that to the same vegetative soul 

 by which fruits and plants are produced is committed the charge of 

 creating the larvae found in galls ! * An instance truly humiliating how 

 little we can infer, from a man's just ideas on one point, that he will not 

 be guilty of the most pitiable absurdity on another ! 



Though by far the greater part of the vegetable excrescences termed 

 galls are caused by insects of the genus Cynips, they do not always ori- 

 ginate from this tribe. Some are produced by weevils of different genera 

 and species. Thus those on the roots of kedlock (Sinapis arvensis) I 

 have ascertained to be inhabited by the larvae of Nedyus contractus and 

 assmrilis. From the knob-like galls on turnips, called in some places the 

 ambury^ I have bred another of these weevils (Curculio pleurostigma Marsh., 

 Rynchfsnus sulcicollis Gyll.) and I have little doubt that the same insects, 

 or species allied to them, cause the clubbing of the roots of cabbages. 2 It 

 seems to be a beetle of the same family that is figured by Reaumur 3 as 

 causing the galls on the leaves of the lime-tree. Mr. Westwood has 

 traced the transformations of a minute species of Balaninus, which resides 

 in the large and fleshy galls on the leaves of willows, occasionally in com- 

 pany with the larvae of Nematus intercus; Bouche has also described the 

 larva of Balaninus salicivorus Schon., which is found in the galls on the 

 leaves of Salix vite/lina, and that of Gymncetron villosul-us, which lives in a 

 gall formed on Veronica beccabunga. According to Hammerschmidt Cleopus 

 ajfinis also resides in galls upon the roots of Sinapis arvensis, Cleonus Li- 

 narics in galls at the roots of Antirrhinum Linarifs, and Saris ctsrulescens in 

 the stems of Reseda lutea, all in their larva state 4 ; and Mr. Ferris has 

 obtained an Apion {A. ulicicola P.) from galls on the young branches of 

 Ulex nanus 6 , an interesting fact, as proving, with a similar one observed 

 by Mr. Westwood as to Apion Radiolum which he found undergoing its 

 transformations in the stems of the hollyhock 6 , 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 



1 De Insectis, 233, &c. 



8 Mr, Westwood informs us that he has not detected any other larvae in the clubs 

 at the roots of cabbages than those of a species of Muscidce (Anthomyia brassica), 

 and which had evidently been produced from eggs laid in crevices of the already 

 formed clubs. 



3 Reaum. iii. t. 38. f. 2, 3. 



4 Bouche Naturgesch, &c. and Hammerschmidt Observ. Physlol Pathol. de Plant. 

 Gattarum Ortu, quoted in Westwood's Modern Classif. i. 342. I have some sus- 

 picion that a little weevil, Leiosoma ovatula, of which 1 found ten or twelve early in 

 the spring of 1842, near Bristol, under the leaves of Ranunculus bulbosus, which they 

 had pierced with numerous holes, may reside in the larva state in galls on the root 

 of this plant. 



3 Ann. Soc. Ent. de France, ix. 90. \Vestwood, ubi supra, i. 337. 



