836 Annual Report for 1890 of the Consulting Botanist. 
difficult to eradicate this parasite, as it attaches itself to the roots of 
clover. If the plants are not dug up, they should be prevented from 
seeding, especially if the clover is intended for more than one year's 
lay. 
Besides samples of rust and mildew, which unhappily do their 
evil work on the wheat crop more or less every year, I have had 
cases of straw blight in barley brought to my notice. The fungus in 
this disease attacks the straw just above the root, and so destroys 
the tissues as to prevent the ascent of the water from the roots, 
and to arrest the active life of the plant. 
Several fields of swedes in Norfolk were attacked by a fungus 
(Peronospora jxirasitica) nearly related to that which produces the 
potato disease. The attack begins on the leaves, and the roots 
{mycelium) of the fungus pass down the leaf-stalks to the bulb, 
where they destroy the flesh, and produce putrefactive decay. The 
turnips may somewhat recover, if the disease is not very severe, by 
the development of several buds around the injured crown. The 
diseased turnips should be destroyed by burning them. If allowed 
to rot on the held or in the manure heap, the hybernating or rest- 
spores will be produced to carry the fungus over the winter, and 
new plants will be produced the following year. 
Another fungus of the same genus (Peronospora Schachtii), 
attacked a crop of mangel in Queen's County. The mangels were 
healthy till the middle of July, when the leaves were attacked 
by the fungus, began to turn yellow, and then to wither. The 
crown became black, and the mycelium passed into the mangel, 
attacking different parts of the root, and producing irregular broken 
canker-looking patches on the outer surface. The diseased mangels 
must be treated in the same way as the diseased swedes. 
A crop of fine walnuts in Bedfordshire was attacked by a 
microscopic fungus (Septoria nigro-maculans), which penetrated in 
every direction the substance of the soft husk that surrounds the 
nut, forming dark brown spots, and discolouring the tissues. In 
the worst specimens the mycelium of the fungus had followed the 
vessels that supply the food to the kernel through the opening 
in the shell, and were consuming the substance of the kernel. 
Nothing can be done to save the injured nuts. The diseased husks 
should all be burned, and, if the disease has reached the kernel, the 
whole should be put into the fire. 
A careful inquiry is being made into the fungus which causes 
canker in the larch. This will form the subject of a memoir in an 
early number of the Journal. 
The results of the inspection of the best ancient pastures in 
England, which occupied the month of August and the half of 
September, have been worked out, and form the subject of a separate 
paper published in the Journal [see page 751 J. 
\Vm. Carrutuers. 
