484 HOMES WITHOXJT HANDS. 



the manner in which a model of a waggon and four horses can 

 find its way into a bottle, the neck of which is so small as to 

 prevent even the head of the waggoner from passing. The 

 answer is similar in both cases. The bottle was ingenioitsly 

 blown over the waggon and horses, and the gall was formed 

 around the grub. 



When the leaf is in its full juiciness, and the sap is coursing 

 freely through its textures, a little black insect comes and settles 

 upon the leaf. She is scarcely as large as a garden ant, but has 

 four powerful and handsome wings, which can be used with 

 much agility. An entomologist, on seeing her, would at once 

 pronounce her to belong to the order hymenoptera, and to be 

 closely allied to the ichneumon flies which have just been 

 described. 



Running to and fro upon the leaf, she fixes upon one of the 

 nervures, and there remains for a short time, evidently busy 

 about some task, which is very impottant to her, but which her 

 minute size renders impossible to be observed with the naked 

 eye. If, however, a magnifying glass be applied very carefully 

 to the leaf, the following process will be seen. 



From the abdomen there projects a tiny hair-like ovipositor, 

 which is coiled in such a manner that it can be protruded to a 

 considerable length. This ovipositor is thrust into the leaf, so 

 as to produce a hole, which is widened by the action of the 

 boring instrument. Presently, the blades of the ovipositor 

 separate, and a single egg is seen to pass between them, so 

 that it is lodged at the bottom of the hole. Into the same 

 aperture is then poured a slight quantity of an irritating 

 fluid, and the insect flies away, having completed her task. 

 The whole proceeding, indeed, is, with the exception of the 

 deposition of the egg, precisely the same as that which takes 

 place when a wasp uses its sting, the ovipositor and sting 

 being but two slightly different forms of the same organ, and 

 the irritating fluid of the cynips being analogous to the poison of 

 the wasp. 



The effect of the wound is very remarkable. The irritating 

 fluid which has been projected into the leaf has a singular effect 

 upon its tissues, altering their nature, and developing them into 

 cells filled with fluid. As long as the leaf continues to grow, 

 the gall continues to swell, until it reaches its full size, which is 



