TREES AND SHRUBS 



They may l>e found growing either singly, in groups of 3-0, each being 



perfect in shape, or in conglomerate clusters consisting of several galls more 



or less fused together. They are not usually borne by fully developed trees. 



The ova are deposited in a leaf-bud towards the end of September or early 



in October. A small swelling is formed on the twig, but does not increase 



much in size till the following April or May. Growth then continues, and 



by the end of September the gall has become firm and hard, and is of a 



yellowish-brown or reddish-brown hue. It may remain attached to the twig 



for several years. The question of an alternate sexual generation is still an 



open one, but it has been considered likely that it will be found in the 



Turkey Oak Hud Gall (Andricus circulans). 



The species of galls above mentioned are some of the easiest to find, but 



there are many more of extreme interest, and the reader who wishes to 



pursue the study may be referred to Connold's " British Oak Galls," a work 



to which we are indebted for much recent information. 



The Robin's Pincushion, Rose Bedeguar or Moss-gall, is the work of 



Rhodites roses, an insect belonging to the Cynipidae. The greenish, pink, 



or crimson gall is formed by ova being deposited in a leaf-bud, each egg 



becoming surrounded with layers of sap, and ultimately making a mass of 



30-45 cells concealed beneath a covering of many-branched fibres. The 



globular conglomeration of cells may reach nearly 2 ins. in diam. The 



larvae pupate in the gall, and the imagines emerge during June. 



Rhodites eglanteriae forms small, smooth, globular galls on the leaves and 



petioles of Dog Rose and Sweet Briar. They are attached by a delicate 



pedicel, and are unilocular and unilarval. They may be found from July 



till October. The larva pupates in the gall, and the imago emerges during 



the following spring. 



Horse-bean Galls, so familiar on the edges, and on either side of the 



midrib of willows, is caused by a Saw-fly (Nematus galMcola). The gall is 



equal in proportion on both surfaces of the leaf, and is green, suffused with 



red, pink, or purple. The larvae, when full fed, generally burrow into the 



soil, and there pupate. The imagines, which emerge in August and Sep- 



liv 





