How Animals Work. 



received a great deal of attention, and the Gall-flies 

 which produce them have been studied and described. 

 Each species of Gall-fly generally appears to have its 

 own particular plant to which it always repairs when 

 on egg-laying intent ; indeed, it is frequently found to 

 confine its attentions solely to one part of the plant or 

 tree, as the case may be ; and where a plant is frequented 



by more than one species, 

 it will be found that one 

 of the Gall-flies deposits 

 its eggs only in the leaf 

 tissues, another only in 

 the tissue of the stalks, 

 and a third, perhaps, on 

 the main stem or roots. 



One of the best known 

 of our British galls, the 

 large and often beauti- 

 fully coloured one to be 

 found on both wild and 

 cultivated rose bushes in 

 almost any part of the 

 country, is produced by 

 the little Rose Gall-fly, 

 known to science by the name of Rhodites rosce. 

 Although this gall looks just as if it arose from part 

 of the stem or twig of the rose bush, it is really a 

 leaf gall, and the manner of its production is rather 

 remarkable. The little female Rose Gall-fly in the 

 spring of the year may often be seen by those who 

 know her busily engaged in hunting over the rose 

 bushes seeking a suitable spot for depositing her eggs. 



252 



Rose Gall. 



