HYMENOPTERA. 433 



Cynips gallod tinctorm, on a kind of oak, growing in the west- 

 ern part of Asia; and the insect may often be found in those 

 whicli are not pierced with holes. Some galls contain only a 

 single insect, lodged in a little cavity in the centre; other kinds 

 are inhabited by several grubs, each in a cell by itself, and the 

 cells notunfrequently resemble numerous small seeds, clustered 

 together in the middle of a fruit. Two or three different kinds 

 of insects are often found to come from one gall, namely, a 

 few gall-flies, which are the lawful proprietors thereof, and 

 more numerous four-winged flies (Chalcidid.e), with elbowed 

 antennce. The latter are bred from grubs, which devour the 

 grubs of some of the gall-flies, or starve them by eating up 

 their food, and thereby contribute to check the too great in- 

 crease of the gall-flies. 



The largest galls found in this country are commonly called 

 oak-apples. They grow on the leaves of the red oak, are round 

 and smooth, and measure from an inch and a half to two 

 inches in diameter. This kind of gall is green and somewhat 

 pulpy at first, but, when ripe, it consists of a thin and brittle 

 shell, of a dirty drab color, enclosing a quantity of brown 

 spongy matter, in the middle of which is a woody kernel about 

 as big as a pea. A single grub lives in the kernel, becomes a 

 chrysalis in the autumn, when the oak-apple falls from the 

 tree, changes to a fly in the spring, and makes its escape out 

 of a small round hole which it gnaws through the kernel and 

 shell. This is probably the usual course, but I have known 

 this gall-fly to come out in October. The name of this insect 

 is Cynips conjluens* Its head and thorax are black, and are 

 rough with numerous little pits and short hairs; the hind body 

 is smooth, and of a shining pitch color; the legs are dull 

 brownish red; and the fore wings have a brown spot near the 

 middle of the outer edge. Its body is nearly one quarter of 

 an inch long, and its wings expand five eighths of an inch. 



A dwarf oak (Quercns infectoria), growing on the borders 

 of the Dead Sea, produces galls somewhat like the foregoing, 

 which have been supposed to be the apples of Sodom, described 



* Diplolepis conflue^ttus of my " Catalogue," and so named by Mr. Say. 



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