1904] SMITH—PUCCINIA ASPARAGI 4I 
could be found than this. Fig. 21 is along the same line, showing a 
low corner of a hundred-acre asparagus fleld, which portion remained 
green much after the tops in the drier portion of the field were dead. 
The water from irrigation accumulated here in the rusty season, 
with the effect described and illustrated. 
o.—Effect of Riga in region of dry soil and abundant dew. Near 
San jae Calif. , August 20, 
The water-relation of Puccinia Asparagi may be thus summarized: 
DIRECT RELATION. 
By direct relation is meant the effect of moisture (necessarily 
atmospheric, except possibly in connection with the germination of 
the teleutospores, which has not been touched upon) acting directly 
upon the spores or mycelium of the rust. This relation has proved 
to be of foremost importance when absolute conditions prevail. It 
has been attempted to show: 
That dew is of absolute necessity in infection by the rust and of 
More importance than rain. 
