492 HOMES WITHOUT HANDS. 



upon the tree is rather larger than the leaf-gall insect, and is of 

 more slender proportions. It has been suggested that the object 

 of the leafy or hairy covering is, that the insect, which remains 

 in the gall throughout the winter, should have a warm house 

 by which it may be protected from the chilling frost as well as 

 from the wind and rain. 



It the reader will again refer to the illustration, he will see 

 that from the same branch on which the Cynips Kollari has 

 formed so many galls, depend two slender threads support- 

 ing one or two globular objects. These are popularly called 

 CuERAMT-GALLS, because they look very much like bunches of 

 currants from which the greater part of the fruit has been 

 removed. Their colour, too, is another reason for giving them 

 this name, as they are sometimes scarlet, resembling red 

 currants, and sometimes pale cream colour, thus imitating the 

 white variety. 



These galls are placed upon the catkins of the oak, which are 

 forced to give aU their juices to the increase of the gall, instead 

 of employing them on theii- own development. Some authors 

 think that the insect which forms them is a distinct species, 

 while others think that the galls are the production of the 

 same insect which forms the leaf-gall, the punctures being 

 made in the stalk of the catkin and not in the nervure of the 

 leaf 



That this supposition may be correct is evident from the fact 

 that the same insect which forms the oak-apples does also deposit 

 its eggs in the root of the same tree, causing large excrescences 

 to spring therefrom, each excrescence being fiUed with insects. 

 I have often obtained these root-galls, several of which are now 

 before me, some having been cut open, in order to show the 

 numerous cells with which they are filled, and others left un- 

 touched, in order to exhibit the form of the exterior. Being 

 nourished by the juices of the root, they partake of the sombre 

 hues which characterise the part of the tree from which they 

 spring, and do not display any of the colours which are seen on 

 the oak-apples which spring from the twigs. 



There are, however, distinct species of gall insects which pierce 

 the roots of the oak-tree. One of them is termed Cynips aptera, 

 and makes a pear-shaped gaU about one-third of an inch in 



