OBSERVATIONS ON THE CALIFORNIA VINE DISEASE 115 
In 1892 Viala and Sauvageau also published a note on the 
California vine disease in the Comptes Rendus, and a memoir on 
the Brunissure and the California vine disease in the Journal de 
Botanique, which was republished later in the Annales de l'École 
Nationale d'Agriculture de Montpellier. These authors described 
the anatomical features of the California vine disease very 
accurately, as I shall have occasion to point out later, and con- 
cluded that this malady was produced by a myxomycete very 
similar to the organism causing Brunissure ( Plasmodiophora 
Vitis), but as it was infinitely more destructive they gave it 
specific rank under the name Plasmodiophora californica. 
In recent years Ravaz' has advanced the opinion that the 
California vine disease and the Brunissure are one and the same 
malady, both being due to overbearing, but the description I give 
of the latter disease in chapter III will show that this view is 
incorrect. If we modify, however, Ravaz's opinion to read that 
the Brunissure killed a number of the vines during the epidemic 
of 1886 in southern California, I think that it can then be sup- 
ported on grounds. But I shall not attempt to advance the argu- 
ments in favor of this modification of Ravaz's view; it would 
lead me too far to do so adequately, and a brief presentation is, 
in the nature of the subject, impossible. 
II 
Description of the California vine disease 
А. MORPHOLOGY 
The California vine disease affects primarily the leaves, fruit, 
shoots, and canes. The arms and trunk reveal nothing of diag- 
nostic value, and an examination of the roots is fruitful in con- 
tradictory results. 
The leaves, fruit, shoots, and canes show symptoms that are 
constant from one variety, or species, of vine to another, the 
observable discrepancies being due to the fact that the virulence 
végétation de la vigne. 
'Ravaz, L. Influence de la surproduction sur la 
Ann. École Agric. Montpellier, II. 6: 5-41- 1906. 
emarques sur le dépérissement de quelques vignes 
.  Progrés Agricole 44: 41-50, 71-73. 1905. 
en Tunisie et en France. 
