4 British Vegetable Galls 



while its surface is dried by the external air, and hardens into 

 a vaulted form." 



Many galls, however, do not begin to grow until the larva 

 is hatched and commences to eat. 



Redi (" De Insectis," p. 233 et seq), not having witnessed 

 oviposition by the parent fly, assumed that the " plant had 

 a vegetable soul which presided at the origin of galls, with 

 their eggs, larvae, and imagines, while it again gave issue 

 to fruits." 



About the middle of last century the true nature of galls 

 began to be understood. 



In Tomlinson's Cyclopaedia, published about 1850, in the 

 section "Gall-Nuts," p. 735, the following appears: "These 

 galls are produced by the punctures of an insect Cynips gallce 

 tinctoricB, which deposits its eggs in the vegetable tissue, and 

 thereby causes the shoot or bud to swell, and become an 

 excrescence or gall, within which the larva is developed." 

 Another publication of the same kind, in circulation about the 

 same date, states that " galls are the result of morbid action 

 excited in the leaf-buds of sev^eral species of the genus Quercus, 

 or oak, occasioned by an insect Cynips quercus depositing its 

 ova in the bud." Kirby and Spence (Intro, to " Entomology," 

 ed. 7, p. 254), in describing " vegetable excrescences termed 

 galls," state that "all these tumours owe their origin to the 

 deposition of an egg in the substance out of which they grow." 

 Rev. J. G. Wood (" Homes Without Hands," p. 484), after 

 describing the operations of the parent insect depositing the 

 ova, continues : " The effect of the wound is very remarkable. 

 The irritating fluid which has been projected into the leaf has 

 a singular effect upon its tissues, altering their nature and 

 developing them into cells filled with fluid. As long as the leaf 

 continues to grow, the gall continues to swell, until it reaches 

 its full size, which is necessarily variable, being dependent on 

 that of the leaf" Edward Steep was of the opinion that "the 

 egg or the fluid which is ejected with it causes irritation in the 

 plant, and an effort is made to cover up the annoying substance." 

 Dr. Stratton (" Alternating Generations," p. 9) says : " A gall 

 is an abnormal growth of plant tissue produced by animal 

 agency acting from within." The " Encyclopaedia Britannica," 

 vol. x., contains a long article on the subject. The following 



