272 THE FLORAL WORLD AND GARDEN GUIDE. 
the purpose. It matters little what the material is or whether it be 
fertilizing. What is of most importance is to add a little nitre, 
which actively promotes the formation of the mushrooms. The 
covering is then lightly patted down with the hand or a spade. 
From time to time the bed should be wetted, so as to keep it rather 
damp. Too much water would destroy the mushrooms. 
A bed like this will quickly yield, and may be made to last five 
or six months. 
In picking, care must be taken to twist off the mushrooms, so as 
not to disturb the bed or pull up the spawn from which they spring. 
If fresh spawn is wanted for other beds, all that is necessary is to 
leave the mushrooms that first make their appearance untouched ; 
when the cap is well open, the spores are formed. Some days later, 
the surface portions of the bed which have become impregnated 
with the white filaments forming the spawn, are set aside, in a barn 
or cellar, in thin layers, where they will keep until required to form 
new beds. 
THE WALNUT. 
BY ALEXANDER M‘KENZIBE, 
Alexandra Palace, Muswell Hill. 
3HERE is no tree more valued than the walnut, when it 
| produces a good crop; and there is no tree that people 
treat with such complete indifference when it does not 
happen to gratify them with a bountiful harvest. In 
this respect it differs from other trees, and the difference 
is, to some extent, not a botanical or horticultural, but a moral 
question. When the apple-trees fail, we hear of it, for there is great 
anxiety ; when the walnut-trees fail there is nothing said. And yet 
when the walnut bears a heavy crop there is great delight, and, as a 
matter of course, all who are interested in the culture of fruits and 
nuts would be glad if they could be shown how to insure an annual 
crop of walnuts, because of the annual joy that would accompany 
the result. Now to begin my story—which will be but a short one 
—I shall say that I will not undertake to give directions for imsur- 
ing constant fruitfulness ; but I will endeavour to direct attention 
to one frequent cause of failure. 
The walnut is one of the most tender trees of the British sylva, 
and a common cause of its barrenness is frost in the month of May. 
Now there are not many people see the truth by the light of this 
simple fact. If they would look at their walnut-trees at the end of 
May, supposing a frost had occurred about the 20th, they would find 
many of the young shoots as black as ink, and yet very soon after 
the trees might be as green and healthy-looking as could be desired. 
A tree may make fresh shoots after a pinch, but it will not produce 
a second crop of fruit. I have seen walnut-trees killed back every 
year for seven in succession, and then, escaping for a season, they 
have borne an abundance of nuts. It follows that when walnut-trees 
are planted, the question of climate should be considered, and if the 
