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1904] SMITH—PUCCINIA ASPARAGI 23 
thrifty are likewise on the heavier soils, other things being’ even 
approximately equal. Most of the growers in the large eastern 
asparagus districts recognize this, and likewise attribute the marked 
freedom from rust of the past two seasons to the very unusual rain- 
fall, which fact is in itself strong evidence of the unfavorable effect 
of abundant soil moisture upon the fungus. 
This is, of course, contrary to the established principle above 
mentioned that such parasites are greatly favored by wet seasons. 
One of the most prominent features in the observations of Stone and 
Smith was the occurrence in the asparagus beds least affected of the 
teleuto stage alone coming on at the usual time, but not preceded by 
any trace of the other stages, so far as could be found by thorough 
search. These beds were, as just mentioned, upon soils of high 
water-retaining capacity. Furthermore, as brought out by two 
extreme seasons, in a very dry summer (1897) the uredo stage appeared 
upon some beds which never showed it before or since, while in a 
season of excessive rainfall (1898) some of the places most affected 
with red rust in other years had only the teleutospores late in the 
season. 
These facts were regarded as showing the indirect relation of the 
rust fungus to water. In the dry seasons and upon the drier soils 
lack of moisture unquestionably reduced the vitality of the asparagus 
plants. Consequently, they became more susceptible to disease and 
suffered in inverse proportion to the amount of soil moisture available. 
As to the direct relation of the parasite to water, the conclusion must 
be drawn from the observations of these investigators that the host- 
plant, depending upon the soil, felt the effects of unusual dryness to a 
more Serious extent than did the parasite, thus turning the balance 
more strongly in favor of the latter; while, on the other hand, in a 
wet season or heavy soil the asparagus derived more benefit from 
such conditions than did the fungus, and thus the activity of the 
latter was checked. In other words, the fungus appeared to obtain 
sufficient moisture for its requirements even in the dry season, and 
received no proportionate invigoration from an excess of moisture in 
seasons of abundant rainfall. It is also indicated by these observa- 
tions that the uredo stage is characteristic of conditions favorable to 
the fungus, while in the unfavorable seasons or localities no develop- 
