OF GALLS AXD VARIOUS EXCRESCENCES. 263 



two in each berry, both consequently flattened on one 

 side. The former grows in barren open places, in 

 situations sufficiently favourable for tiie impregnation 

 of its blossoms, but far less so for the perfecting of 

 much seed ; while the latter, ^\■e\l supplied with manure 

 and moisture, is enabled to bring every germ to ma- 

 turity. 



Very strange effects are often produced upon plants 

 by the attacks of insects, \\ hence the various kinds of 

 Galls derive their origin. These are occasioned by the 

 punctures of those little animals, rhieiiy of the Hi/men- 

 optera order, and of the genus Cynips, in some vigo- 

 rous part of the plant, as the leaves, leaf-stalks, young 

 stem or branches, and sometim.es the calyx orgermen. 

 The parent insect deposits its egg there, which is soon 

 hatched ; and in consequence of the perpetual irritation 

 occasioned by the young maggot, feeding on the juices 

 of the plant, the part where it is lodged acquires a 

 jiiorbid degree of luxuriance, frequently swelling to an 

 immoderate size, and assuming the most extraordinary 

 and whimsical shapes. This often happens to the 

 shrubby species of Hawkweed, Hkrociiun sahciudiDny 

 Engl. Bot. t, 349, and umhdlatnm, t, \17\-, whose 

 stems in consequence swell into oval knots. Several 

 different kinds of Galls are borne by the Oak, as those 

 light spongy bodies, as big as walnuts, vulgarly named 

 Oak apples; a red juicy beny-like excrescence on its 

 leaves ; and the very astringent Galls brought from the 

 Levant, for the purposes of dyeing and making ink. 



