498 HOMES WITHOUT HANDS. 



■would scarcely be recognised as galls except by an experienced 

 eye. Miey are, however, the production of an insect called by 

 entomologists Cynips polyeera. 



These galls are found in many parts of Gennany, upon the 

 oak-tree, and are at once recognised by their remarkable form. 

 As may be seen by reference to the illustration, they are shaped 

 something like miniature sugar-loaves, and stand boldly fiom 

 the branch with their broad end uppermost. The body of the 

 gall is slightly conical, so that if cut transversely, it would 

 present a circular sectioa The end, however, is constructed 

 after a peculiar fashion. 



It is nearly flat, " abruptly truncated " according to scientific 

 language, and throws out several projections like horns or spines. 

 The reader will remember that the ink-gaU also possesses short 

 and sharp projections, but they start from aU parts of the surface, 

 whereas in the present species they belong wholly to the flat- 

 tened end. Their number is variable, so that the end of the gall 

 is sometimes triangular, and sometimes squared, beside assuming 

 other forms according, to the number of projections. This re- 

 markable form has earned for the insect the name of polyeera, 

 this term being derived from two Greek words which signify 

 "many-homed." The insect which forms this ciirious gall is 

 about half as large as Cynips Kollari. 



The last example which is represented in the illustration is 

 also found in Germany upon the oak, and is made by an insect 

 which is called Cynips Hungarica. 



This gall is represented of the natural size, whereas all the 

 others are much diminished, in order to be inserted in so limited 

 a space. It is a very remarkable object, and cannot be mistaken 

 for any other species. Its surface is traversed by a variable 

 number of irregular ridges, which all radiate from the stem, and 

 so pass longitudinally over the gall The whole of the ridges 

 are rough and sharp-edged, but at intervals they shoot out into 

 hard-pointed horns, much like those which arm the preceding 

 species. Indeed, the whole substance of the gall is remarkable 

 for its hard texture, for when cut with a knife it offers as stub- 

 born a resistance as if it were seasoned oak or elm. 



That a hymenopterous insect should be able to bore its way 

 through so hard a substance, and to make a tunnel barely wide 



