386 Philip: The Uredinee. 
ing among the stubble. Evidently the ecidium may be derived 
from the rust on the rye, but it is not easy to understand how 
the converse can occur, and the rust on rye be derived from an 
zecidium that appears only after the rye is cut, and that is dead 
long before the shoots of the next year appear. 
The hetercecious fungus found on Senecio and known as 
Coleosporium senecionts has its zcidium stage as what was called 
Peridermium pint on the pine. Now in this case the uredo- 
and teleutospores are formed during summer and autumn on 
the deciduous leaves of Senecio jacobee, and the annual leaves 
of S. vulgaris, viscosus, and sylvaticus, on none of which can they 
be expected to survive the winter, while the zcidium which 
appears in May and June on the pine, would seem to have a 
much better chance of survival if it remained where it was, 
since the pine leaves are evergreen. Anyway, the purpose of 
tiding over the winter can scarcely be the explanation why it 
forsook the hardy pine for the more delicate Senecios. 
Once again, if the necessity of tiding over the winter is the 
chief cause of hetercecism, how is it that certain species, such as 
Melampsora helioscopie on the spurge, and Coleosporium eup- 
vasi@ on the eyebright, and Puccinia prenanthis on wall-lettuce, 
fungi which exist on plants annual in duration, are not heterce- 
cious ? It is apparently the only chance they have of main- 
taining themselves. The annual plant perishes entirely and 
the fungus in its tissues must perish too unless it can find a 
place of safety with some other host. The probable explana- 
tion in this case is that very likely our knowledge is not perfect 
and that some portion of its existence is passed either on the 
ground, or on some other host plant. It is easy to believe 
that a fungus may be continued from year to year in a perennial 
plant and itself become perennial likewise, but the perpetuation 
of a parasite on an annual plant presents difficulties for solution. 
Ole 
FLOWERING PLANTS, etc. 
Cherry Galls at Ripon.—The willows bordering the right 
bank of the river Ure at Ripon, below the North Bridge, are 
presenting now a most remarkable appearance owing to the 
enormous quantity of cherry galls which crowd the smaller 
stems and twigs. These are so numerous, they attract the 
notice of even unobservant eyes, and give to the bushes the 
appearance of bearing a rich crop of ripe fruit. The galls 
are bright red in colour, fading into green, and are presumably 
those of a variety of Saw Fly. In numbers and size they rival 
the berries upon neighbouring hawthorn trees, but are scarcely 
so richly tinted.—A. LESLIE ARMSTRONG, Harrogate. 
Naturalist, 
