Chap. 37.] 



THE DISEASES OE TREES. 519 



comparative amount of sap that they contain ; while some, 

 again, are troubled with obesity, as in the case of all the re- 

 sinous trees, which, when suffering from excessive fatness, are 

 changed into a torch-tree. 80 When the roots, too, begin to 

 wax fat, trees, like animals, are apt to perish from excess of 

 fatness. Sometimes, too, a pestilence 81 will prevail in certain 

 classes of trees, just as among men, we see maladies attack, 

 at one time the slave class, and at another the common people, 

 in cities or in the country, as the case may be. 



Trees are more or less attacked by worms ; but still, nearly 

 all are subject to them in some degree, and this the birds 82 are 

 able to detect by the hollow sound produced on tapping at 

 the bark. These worms even have now begun to be looked 

 upon as delicacies 83 by epicures, and the large ones found in 

 the robur are held in high esteem ; they are known to us by 

 the name of " cossis;" and are even fed with meal, in order 

 to fatten them ! But it is the pear, the apple, and the fig 84 

 that are most subject to their attacks, the treesthat are bitter 

 and odoriferous enjoying a comparative exemption from them. 

 Of those which infest the fig, some breed in the tree itself, 

 while others, again, are produced by the worm known as the 

 cerastes ; they all, however, equally assume the form of the 

 cerastes, 85 and emit a small shrill noise. The service-tree is 

 infested, too, with a red hairy worm, which kills it ; and the 

 medlar, when old, is subject to a similar malady. 



The disease known as sideration entirely depends upon the 

 heavens ; and hence we may class under this head, the ill 



80 See B. xvi. c. 19. He alludes to an exuberant secretion of resin, in 

 which case the tree becomes charged with it like a torch. 



81 He alludes to the epidemic and contagious maladies by which trees 

 are attacked. The causes of these attacks are often unknown, but they 

 may probably proceed, in mauy instances, from springs of hot water, or 

 gaseous emanations secreted in the earth. 



83 -The woodpecker more particularly. See B. x. c. 20. 



83 It is not known, with certainty, what these worms or caterpillars 

 were. The larva of the Capricorn beetle, or of the stag-beetle, has been 

 suggested. Geoffroi thinks that it may have been the larva of the palm- 

 weevil. This taste for caterpillars, probably, no longer prevails in any 

 part of Europe. 



84 This passage, which is quite conformable to truth, is from Theo- 

 phrastus, Hist. Plant. B. iv. c. 16, and B. iii. c. 12. 



85 See B. xvi. c. 80. 



