Ailanthiculture. 227 
nected low down, they present a series of cul-de-sacs, in which any 
object penetrating would be at once involved and entangled; the 
silk too is very close and tough and requires considerable force and 
perseverance to rend it. Hence, though I have cocoons which 
have been attempted by tomtits, earwigs, Carabi, &c., I have not 
observed that they ever succeeded in gaining an entrance into a 
normal cocoon, though they might readily penetrate the slight 
cocoon of a weak and sickly larva. Lastly, these loops all pre- 
senting inwards are easily pushed back and opened outwards by 
the insect when making its exit, and they likewise prevent the 
pupa-case from following the newly-born imago. When the insect 
has emerged it is very easy to recognise the fact, as the cocoon 
is much lighter in weight, some of the flue from the body of the 
moth is retained at the exit hole, and the latter is considerably 
dilated and now admits the easy entrance of a pencil or probe, &c. 
In about 10 or 12 days after commencing to spin, the larva 
changes into a pupa, and then the cocoons may be strung up in 
chaplets, care being taken, by shaking each cocoon, to test the 
presence or absence of parasites; those cocoons of a darker 
colour than usual, not a bright rusty brown but of a dingy hue, 
should be suspected and carefully examined. Some time during 
the autumn many of the parasites will emerge, but not all. But I 
recommend that all doubtful cocoons be at once boiled to kill the 
parasites, and then reeled. 
The duration of life in the egg state varies from 10 to 18 days, 
according to the temperature; in the larva state from 30 to 60 
days; in the pupa state from 3 to 4 weeks in autumn, or during 
the whole winter; in the imago state it is 8 days. 
The finer the insect the longer time will it require for growth. 
Introduced into France in 1856, the success of Ailanthiculture 
is now sufficiently attested by the experience of successive years, 
In England no one, so far as I am aware, except a Mr. Mongredien, 
who has an extensive young Ailanthery at Bratton Clovelly, North 
Devon, had on a large scale, prior to 1865, attempted Ailanthicul- 
ture “en plein air.” It had been demonstrated by Lady Dorothy 
Nevill and others, that the tree and insect throve well in our climate, 
but it was feared that birds and other enemies would create such 
havoc as to render the crop precarious, and this seemed likely 
from experiments carried on in gardens on a small scale, a state 
of things manifestly very different from that under which Ailane 
thiculture must (if ever) be carried out in this country as an in- 
dustry. Aeres and acres will be planted with Ailanthus trees in 
the open air, away from woods, plantations or dwellings, either 
