April 29, 1905. 
THE GARDENING WORLD 
359 
and address us in plain language. 1 have wrestled manfully 
witli his sentence referring to the B.G.A. He says: ‘.‘The 
primary condition of eligibility is at least live years’ training." 
Have we to infer from this that live years’ training makes a 
gardener? Will " Homocea ” kindly explain? 
As to my sitting on the fence', as “ H.” so elegantly terms 
it, I am glad to say I sit in good company, and not even the 
honour (?) of a seat beside the popular “ Homocea ” will tempt 
me to leave my present friends. As to' the sneer anent 
“ Cabbager’s ” letter, I would only say that its common sense 
and pointed remarks must be so' unpalatable to “ Homocea ” 
that he pretends not to understand it. C. Blair. 
Primula megaseaefolia. 
To the Editor of The Gardening World. 
Sir,—In recent issues of The Gardening World mention 
has been made concerning the dimorphic character of this 
Primula. 
Two years ago I had three plants of this species, and, con¬ 
trary to the experience of your correspondents on this subject, 
they were all pin-eyed and long-styled. 
The plants were cultivated in a cold greenhouse by the side 
of a hatch of P. kewensis, and although every care was taken 
to induce P. megaseaefolia. to seed, yet it never produced a 
single fertile seed. 
At that time I wished very much that I could have procured 
a. thrum-eyed form and so. have crossed the two forms, for I 
was successful in obtaining fertile seed from other species by 
so doing. 
It. would be interesting to cross the two forms and note the 
result, for if thrum-eyed, self-fertilised, produces seed freely, 
then pin-eyed x thrum-eyed and vice versa should produce an 
even greater abundance of fertile seed. 
Many strong arguments may be brought against Darwin’s 
views on the fertilisation of the genus Primula, such, for in¬ 
stance, as the time of flowering, for many Primulas flower 
before bees and other flower-visiting insects are on the wing ; 
also in the case of the thrum-eyed form, the pollen is produced 
above the pistil and must therefore' fall on to' it when the 
anthers shed their pollen. 
My own experiments favour the views of the great naturalist 
(see “ The Primrose find Darwinism,” August, 20th and 27th, 
1904, which I think is important to- those who wish to seed 
Primulas). 
There is no tiine like the present for studying the common 
Primrose, and those who avail themselves of the opportunity 
may, perhaps, throw new light, upon this subject. 
Herrert Cowley. 
The Snowy Fly. 
Several species of fly belonging to' the genus Aleyrodes are 
known under the tends of Snowy Fly or Holy Ghost Fly. 
Three of them are recorded in this country as injurious to 
various plants when they occur in large numbers, as they 
usually do when circumstances are favourable'. Some of them, 
at least, would be natives to this country or come from coun¬ 
tries with a similar climate. They would include those species 
which attack plants in the open air. The Cabbage Powdered- 
wing, which attacks the Cabbage and other members of the 
same tribe, is one of these. 
There is, however, another species which is far more trouble¬ 
some to cultivators of plants under glass. In this country 
Ferns and Tomatos are the first to suffer and receive the 
greatest amount of damage. This is Aleyrodes vaporariorum. 
It has been made the subject of inquiry on the part of the 
Division of Entomology of the U.S. Department of Agriculture, 
and a Bulletin on the white fly has been issued. 
It seems that the fly is more frequent and destructive there 
than in this country. The total crop of Tomato® and 
Cucumbers has been lost in some instances on account of the 
depredations of myriad numbers of this little marauder. While 
several species of snowy fly confine their attentions to one plant 
or class of plants, the greenhouse species is notable for its 
general feeding habits. It has been found and recorded on at 
least sixty different species of plants, including a great variety 
of subjects grown in the stove and greenhouse, and including 
both flowers and vegetables. It is admitted, however, that the 
Cucumber and Tomato are the most likely to suffer serious 
injury on the part of this insect. 
Those who have not yet been troubled with this insect in 
their glasshouses are advised to keep an eye upon the fresh in¬ 
troductions to their establishments. Plants brought from 
other places should be examined, and if any doubt on the point 
exists the new introductions should be placed in an airtight 
box and fumigated before being placed amongst other plants. 
The most effective insecticide in this case has been found to be 
fumigation with hydrocyanic acid. Its success is chiefly due to 
the fact that the perfect, insect and the larvae, can be destroyed 
by a small amount of gas, to which they should be exposed for 
a. considerable length of time. Tomatos and Cucumbers are 
very liable to injury from the gas, so that it is valuable to 
know that a. small amount of gas may be effective in destroying 
the fly merely by keeping the house closed for a longer period 
when the gas is being employed. 
One-fifth or one-sixth ounce of potassium cyanide will lie 
sufficient for a thousand cubic feet of glass enclosed space, pro¬ 
vided the house is kept closed for three hours. It is impossible 
to give exact and precise directions for the amount of the 
fumigation to be used in any given house, as it depends largely 
upon the airtight condition of the glass of the houses or other¬ 
wise. Thus it would be necessary to have some idea of the 
close-fitting character of the glass in the house to be fumigated 
before it would be safe to use any given amount of the 
fumigant. 
This would necessitate a knowledge of the condition of the 
houses and even a tentative trial by using a quantity under 
rather than over the amount supposed to be necessary. If the 
first trial was not- quite effective and the plants were perfectly 
uninjured, the operator could safely apply a stronger dose of 
the remedy. 
It has still to be admitted that the eggs and late pupae stage 
of the insect are not affected to such a degree by the fumiga¬ 
tion as to prevent them from hatching out afterwards. This 
would necessitate the fumigation of affected houses at intervals 
so as to destroy successive broods of the insect that must 
always be present in houses where they have become firmly 
established. 
Standard Gooseberries. 
Within the last decade or so many amateurs have become 
enamoured of a plan of growing Gooseberries in the form of 
standards. For this form of head it is necessary to have some¬ 
thing that will form a, strong stem that will answer the purpose 
as a, stock for the Gooseberry in the same way that the Brier 
or Dog Rose answers for cultivated varieties of Rose. 
Possibly some varieties of Gooseberries with strong upright 
growing stems might be found suitable as a stock for this pur¬ 
pose, but apparently those, who work the stocks do not seem 
to have discovered any suitable variety of Gooseberry. The 
stock employed at present is the Golden-Flowered Currant 
(Ribes aureum) which grows rapidly and may quickly be had 
of a size and height suitable for grafting or budding with 
Gooseberries. Stocks are veiy easily procured from cuttings, 
as in the case of the garden Currants, and as they grow freely 
and vigorously, strong and straight stems about 4 ft. high are 
quickly obtained. Grafted or otherwise worked upon these 
stems, the Gooseberry grows satisfactorily for a number of 
years, at least, though it doe® not grow at all in a rampant 
manner. 
The plea for growing the Gooseberry in this fashion is that 
the fruits are easily gathered, the bushes have a novel appear¬ 
ance, and they never get splashed with sand as Gooseberries do 
which grow on drooping bushes with branches near the ground. 
A large number of varieties are employed for this purpose, but 
it would be a good idea to grow those varieties which are 
naturally of drooping habit and thereby accomplish two objects 
—namely, getting the bushes well off the ground, and forming 
weeping Gooseberries. 
