516 HOMES WITHOUT HANDS. 



produced by the same insect. These galls are also known as 

 Mala Sodomitica, and Mad Apples, the latter term being the ori- 

 gin of the specific title " insana" applied by Mr. Westwood to the 

 insect. 



Immediately below the Dead Sea Apple, and in the right- 

 hand lower corner, may be seen two remarkable objects, which 

 would- scarcely be recognized as galls except by an experienced 

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

 entomologists Cynips polycera. 



These galls are found in many parts of Germany upon the oak- 

 tree, and are at once recognized by their remarkable form. As 

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

 something like miniature sugar-loaves, and stand boldly from the 

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

 slightly conical, so that, if cut transversely, it would present a cir- 

 cular section. 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 gall also possesses short 

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

 whereas in the present species they belong wholly to the flattened 

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

 sometimes triangular and sometimes squared, besides assuming 

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

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

 this term being derived from two Greek words which signify 

 " many -horned." The insect which forms this curious 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 can not 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 



