8 British Vegetable Galls 



shoots terminate in a tuber, which in Scirpus lacustris Linn, 

 may be as large as a chestnut, and in Sagittaria sagittifolia 

 Linn, the size of a hazel nut. 



Similar features are also found in the bulbous herbs, Scilla 

 nutans Sm. as an example, and in the orchid family also. 



The nodulose growths on roots of Spiraa are conspicuous 

 examples ; but a more familiar example is seen in the thickened 

 roots or pseudo-bulbs of grass. They may frequently be noticed 

 on roadside banks, where the crumbling away of earth leaves 

 them exposed to view ; and while in a semi-buried condition 

 they look very like gall-growths. Some specimens are hollow, 

 and closely resemble the empty larval chamber of a true gall. 

 Two specimens of this kind may be seen in the right-hand 

 side of plate 3. 



Peculiar swellings of the wood and the bark are also shown 

 on plate 4. 



mm 



MILLIMETRE SCALE 



