502 HOMES WITHOUT HANDS. 



In the left-hand upper corner of the illustration is a figure of 

 an oak leaf, upon which are two globular projections. These are 

 the well-known " cherry galls," which are made by a little insect 

 called Cynips quercus -folii. They are beautifully colored, some 

 being entirely scarlet, while others are white, orange, and red, in 

 various gradations, something like the color of a nearly ripe peach, 

 or those of a Newtown pippin. Perhaps they bear more resem- 

 blance to the apple than to the peach, because their surface is high- 

 ly polished and shining, much like that of the American apple. 



These galls may be found in profusion upon the oak leaves, and 

 are most plentiful upon pollard oaks, upon the youngest trees, or 

 upon the oak underwood that sprouts around a felled trunk. In 

 such cases the leaves are much larger, and fuller of juice than 

 those which spring from adult trees, and the development of the 

 gall is proportionately increased. Wherever there is a thick 

 growth of oaken underwood, the numberless galls which stud the 

 leaves have a remarkably beautiful effect, provided that the ob- 

 server lies on the ground, or stoops sufficiently low to perceive 

 the under surface of the leaves, to which the galls are attached. 



If one' of the galls be cut open with a knife, it will be found to 

 consist of a soft pulpy substance, fuller of juice than an apple, and 

 somewhat resembling the consistence of a hothouse grape. In the 

 very centre of the soft mass the knife will meet with resistance in 

 the shape of a globular cell of hard woody texture, and in the 

 middle of the cell will be found a tiny grub, perfectly white, very 

 fat, somewhat resembling the grub of the humble-bee, and curved 

 so as to fit the globular cell in which it lies. This is the little 

 being for whose benefit the gall was formed, and the little white 

 grub feeds on the juices of the gall, precisely as the larva of the 

 ichneumon fly feeds on the soft portions of the insect in which it 

 temporarily resides. 



On seeing the little creature thus snugly ensconced in the re- 

 ceptacle which serves it at once for board and lodging, a question 

 naturally arises as to the manner in which it was placed there. 

 No aperture is perceptible in the gall, not a hole through which 

 air can reach the inclosed larva, which must, therefore, be capable 

 of existing without more air than can pass through the minute 

 pores of the vegetable substance in which it lies, or must be able 

 to respire by means of the oxygen which is given out by living 

 plants. 



The question, indeed, is very like the well-known query as to 



