July 8, 1899. 
THE GARDENING WORLD. 
713 
you sent was the Lacewing Fly (Chrysopa vulgaris) 
rather common British species of the Neuroptera 
order, i.e., those with net-veined wings. It is a 
beautiful little thing often to be seen dying out in the 
dusk of evening and also in the sunshine of the day. 
The eggs may sometimes be seen fastened to little 
footstalks all rranged upon plant stems. These 
insects do good by devtuiing green flies and other 
Aphides, although they also eat otner insects as well. 
A Rootery. — Mr. Finley, Dumfries : Curiously, 
rooteries are not quite so often seen, even in places 
the better for the general, finished effect. Ferns and 
shrubs and various kinds of plants should be largely 
planted, yet with plenty of space between them all. 
INCARVILLEA DELAVAYI. 
One of the prettiest of hardy garden plants of 
recent introduction from China is Incarvillea 
Delavayi, and it is not yet so well known as it 
deserves to be. It comes into flower in early May 
and continues far into June, which is sufficient to 
recommend it to all who have a garden. The 
slight protection, and also at Surbiton in Surrey, and 
South Devon. After these remarks it may be 
described as a hardy border plant, if it has the soil 
and position best suited for it. It prefers a deep, 
rich, sandy loam and a sunny position, with a cover¬ 
ing of about 2 in. of soil over its crowns. It is a 
good plan to see that the soil is annually earthed up 
as the crowns are very apt to be lifted up by hard 
frosts. Planting may take place in September and 
October and in February and March. 
The flowers are a deep rosy-crimson with maroon 
shading, on a scape 2 ft. to 3J ft. high, bearing from 
where tree stumps must be plentiful, as one might 
expect. They are easily formed as regards artistic 
skill, if only a suitable place be chosen and enough 
labour employed. Those who are used to handling 
wood or heavy tree trunks can do the work easily, 
while the awkward man would be gasping, or, to use 
Scotch, “steckin.” In the arranging have them 
variously placed, cocked, angled, flat, bulging, 
receding, in prominences and falls, built and banked 
up with good soil and drainage, rounded or so dis¬ 
posed as to receive moisture. If the site be a bank 
or falling ground with slightly rising banks, so much 
flowers from which the sketch was taken were ex¬ 
hibited at the show of the Epping and District 
Horticultural Society in May.by Messrs. Wallace & 
Co., Colchester, of Lily fame, who had some magni¬ 
ficent spikes of these charming flowers which were 
much admired. I. Delavayi has been proved to be 
perfectly hardy in various parts. For instance, in a 
private garden in Wiltshire these plants are growing 
profusely, and seedlings saved have bloomed out of 
doors the second season. At St. Lawrence, Isle of 
Wight, it succeeds without protection outdoors. In 
Hampshire it does remarkably well with only a 
seven to twelve flowers. The plant has serrated 
pinnate leaves, which are very handsome and of a 
dark green colour, often 12 in. to 18 in. long.— W. L. 
—-—****—— 
Incombustible Thatch. —It has been proved by re¬ 
peated experiments that straw, saturated with a 
solution of lime, or common whitewash, is incom¬ 
bustible. This fact is of great importance to the 
rural population, especially as thatch is thus not 
only rendered fireproof, but much more durable. A 
solution of alum has been tried, but, being soluble, 
the rain destroys its virtues, 
