96 PLANT LIFE. 



" Anthracnose," or " Bird's-eye Rot," and to Phoma 

 ampelinum, which produces sunken pits in the bark 

 with a raised shrivelled margin, and kills the tissues. 



(5) Even the tendrils have a special enemy, Lepto- 

 sphaeria vitigena. 



(6) Amongst the best known diseases of the grape 

 are "Vine Mildew" {Uncinula spiralis), of which the 

 fruit is a brown spherical body surrounded by 

 curious hooked anchoring appendages, which cling to 

 the young leaves or fruit ; the spores germinate in wet 

 weather and destroy part of the fruit ; the grape then 

 bursts because the healthy parts continue to grow. 

 Another is the Sclerotinia disease, which is also found on 

 the fruit. Moreover, if grapes are injured at any time 

 by the bruising of their delicate down or skin, many 

 mould fungi may gain an entrance to the sugary juice, 

 and entirely destroy it. (Notably Penicillium glaucuni 

 and Botrytis) 



(7) The " Mai Nero " which causes the wood 

 of the Vine to decay, is due probably to a Bac- 

 terium. The 16 or 17 fungi mentioned here by 

 no means form a complete list of the enemies of 

 the Vine. (See Tuboeuf ) The spores of these fungi 

 are carried by the wind, or sometimes by bees when 

 they are visiting flowers, and are probably present 

 in enormous numbers when the disease is once 

 established. 



But it will be seen that every part of the plant — 

 leaf, fruit, twigs, stem and root, has its fungus enemies, 

 which are always ready to attack any organ that is 

 at all weakened or defective ; when any fungus has 

 been able to multiply unduly, it is even able to 

 attack sound and healthy plants, and the existence 

 of the species may be endangered. That, however, 



