Inclement Weather^ Diseases, Etc. 293 



[Fig. 114], and the young shoots [Fig. 1 15], whose de- 

 velopment it suspends, then on the berries themselves, 

 whose growth it arrests. The cuticle of the berries hard- 

 ens and assumes a tawny color ; these berries split [Fig. 

 116], acquire a bitter taste, and rot before ripening. 

 The leaves and shoots attacked are covered with brown 

 spots, the leaves drop off, and, if the disease be severe, 

 the shoots themselves are disorganized to their very 

 base, so that not only is the crop of that season lost, 

 but also that of the following year, and if the plants be 

 subjected to this scourge for two or three years in suc- 

 cession, they soon perish. 



It was in 1845 that o'idium was first observed on the vine 

 in England, by Mr. Tucker, a gardener at Margate. Since 

 1849, this disease has shown itself at several points in 

 the neighborhood of Paris ; first on vines in hot-houses, 

 then on garden trellises, and finally on vineyard plants. 

 It has now, unfortunately, invaded all parts of our terri- 

 tory, acting more intensely in proportion as the vines 

 are situated in a hotter climate, or have a warmer ex- 

 posure. It seems to attack all varieties alike, but it 

 acts with greater force on the most vigorous. [!] 



Opinions are very much divided as to the cause of 

 this serious affection of the vine. Some attribute it 

 entirely to that white efflorescence which has been re- 

 cognized as a little parasitical mushroom of the genus 

 oidium of the numerous family of the mucedinee, and to 

 which the specific name " Tuckeri " has been given. 

 Others look upon the presence of this mushroom (which 

 is not called in question) as the result of the disease, 

 and they think it brought about by certain microscopic 

 insects. Finally, others again attribute it to atmos- 



