Ailanthiculture. 219 
failing sign of damage. I have repeatedly found cocoons which 
gave no rattle when shook, and almost without exception I 
have found that damage had accrued to the larva within, gene- 
rally from parasites, which had prevented the change into pupa. 
One remarkable instance I met with: I tried the pupa, it was 
softer and browner than usual, and did not shake; I inferred a 
parasite. Before however cutting open the cocoon I tried another 
plan; I manceuvred the end of a pencil so as to get it within the 
opening of the cocoon, which by-the-by is much more difficult to 
manage in a sound than in an unsound cocoon, and [ found it to 
impinge at once on a solid round body, giving a sensation similar 
to that presented by a pupa; if a shrunken larva be within 
the cocoon the sensation of impingement is quite different and 
the pencil goes in further before impinging: being puzzled I cut 
open the cocoon and found therein a pupa-case, not however of 
the usual light yellow-brown colour, but darker and crackling to 
the touch; it came apart and a yellowish-white parasitic larva 
was within, elongated to a point at one end, occupying nearly the 
whole of the pupa-case. I have kept this parasite, hoping to hatch 
it out, but the test of shaking the cocoon fully disclosed there was 
mischief within. I am not clear whether these cocoons are of equal 
value for winding purposes with the sound cocoons, but I incline 
to think they will turn out to be of less value. 
Amongst birds, tomtits are the most destructive; they plunge 
their beaks inside the larva, making a holeat theside, and suck thence 
the juices; thrushes are reported to do the same. Mr. Calvert tells 
me, that a robin created much havoc in his Ailanthery; and Lady 
Heathcote writes, that a flight of rooks discovered her Ailanthery 
one morning and carried off some fifty larvee, which were on small 
stunted trees. Probably too sparrows would commit depredations, 
and magpies be mischievously inclined. The starling and jackdaw 
are to be feared. Still I am inclined to think that by choosing a 
time in summer when there are other and greater attractions for 
birds, by the use of a gun and of scarecrows, by avoiding the neigh- 
bourhood of rookeries and plantations where tomtits abound, and 
by limiting the time as much as possible during which the larvee 
are “en plein air” without protection, a crop may be harvested 
without much loss from birds. 
Another serious enemy to this larva is a disease which I 
observed last summer, coincident in point of time with the occur- 
rence of the potatoe disease, during the prevalence of very heavy 
and prolonged rain for a period of nearly three weeks from 
August 10th to 28th ; the ground was previously very warm from 
Q2 
