2/0 KEMAUKABLE EXCRESCENCES. 



tufted Lichen, but proved on examination a real Gall. 

 Indeed our Salix Helix, t. 1343, is called Rose Willow 

 from its bearing no less remarkable an excrescence, like 

 a rose, at the ends of some of its branches, in conse. 

 quence of the puncture of an insect, and these are in like 

 manner durable, though the proper leaves foil. The 

 Mastic-tree, Pistacia Le?itiscus, is often laden, in the 

 south of Europe, with large red hollow finger-like bod- 

 ies, swarming internally with small insects, the jiphis 

 Pisfacice of Linnaeus. The young shoots of Salvia po- 

 mifera, FL Grtec. t. 15, S. triloba, t. 17, and even ^S*. 

 officinalis, in consequence of the attacks probably of 

 some Cynips, swell into large juicy balls, very like ap. 

 pies, and even crowned with rudiments of leaves resem- 

 bling the calyx of that fruit. These are esteemed in the 

 Levant for their aromatic and acid fliivour, especially 

 when prepared with sugar. 



It may be remarked that all the excrescences above 

 mentioned are generally more acid than the rest of the 

 plant that bears them, and also greatly inclined to turn 

 red. The acid they contahi is partly acetous, but more 

 of the astringent kind. 



The diseases of the skin, to which many vegetables 

 are subject, are less easily understood than the forego- 

 ing. Besides one kind of Honey-dew, already mention- 

 ed, /). 157, something like leprosy may be observed in 

 Tragopogon major, Jacq. Austr. t. 29, which as I have 

 been informed by an accurate observer, does not injure 

 the seed, nor infect the progeny. The stem of Shep- 

 herd's Purse, Engl. Bot. t. 1485, is occasionally swel- 

 led, and a white cream-like crust, afterwards powdery, 



