1116 General Notes. [De 
troublesome in American green-houses, suggests a similar cause. 
Among those on woody stems are the black knot on species of 
Prunus and the Gymnosporangia on cedars. 
e flower is attacked in the case of the “ double blossom” of 
blackberries, the smuts of many grasses (such as Ustilago raben- 
horstiana on Panicum sanguinale), and other cases that will sug- 
gest themselves. Often the entire inflorescence is arrested in its 
development. Smut of Indian corn attacks both staminate and 
pistillate flowers, and the green parts as well. Ustilago anther- 
upon Caryophyllacee produces its spores in the anthers. 
Tilletia caries, the bunt of wheat, destroys the inner structure of 
the seed, without much changing the external appearance. The 
majority of Ustilagineæ attack the inflorescence, flowers, and 
fruit. 
The young ovary is affected in various ways. Ergot distorts 
it and produces an abnormal, horn-like mass of tissue; smuts 
convert it into powdery spores. Exoascus changes that of 
Prunus into a pouch. Fusicladium kills the newly-formed pe 
5) The last case is also an example of the premature falling 
of diseased parts, apparently by the formation of the separative 
layer before its time. Such a falling of leaves is well illustrated 
by Septoria ribis upon the currant. On the other hand, diseased 
parts may remain green after the other parts have matured in the 
usual way. Ovaries of Eragrostis poæoides filled with Ustilago 
spermophorus are most readily detected by this sign. Probably 
this may be classed as retarded development. hed 
(6) Many fungi cause decay of ripe fruit, both while wine 
to its plant and after removal, while still alive. From a Bee i 
stand-point, the injury to fruit may be of two kinds; it may ater 
simply the appearance, and hence the market-value, or KA 
the quality, when it does not entirely destroy. The scab 0 
apples is injurious in either of these degrees. : 
Some fungi begin their growth as parasites under iai 
conditions, to continue it under conditions more like those wil 
: : be men- 
accompany saprophytic growth; in this connection may plant 
tioned the potato-rot, beginning its growth upon the green till 
: ; r. the $ 
and sometimes completing it in the cellar, but upon 
living tuber. esa- 
(7) Some valuable plants are liable to infection from oth a 
less value; a knowledge of this fact in individual cases iy : 
of great practical utility, as a remedy may be more easly ee 
effectively applied. It is easier to destroy wild grapes s e 
pelopsis than to destroy Peronospora upon cultivate rs y 
which have suffered infection from the wild ones. This F a 
especially commends itself when one stage of the fungus Spa a 
i 
x 
upon one kind of plant and another stage upon another 
-as do cedar-apples and orchard-rusts. M 
Perhaps no line of investigation in economic mycology PF ae 
