Ailanthiculture. 225. 
sary room for movement, for as the silken threads contract they 
would, were it not for the tubercles, close so tightly round the 
body of the larva as to prevent it from completing its work ; but 
observation of the insect during this process shows that the tu- 
bercles not only keep the silken threads away from the body, but 
further promote movement by acting somewhat as feet ; hence the 
larva obtains freedom of movement within its case, and is able to 
continue its work for nine or ten days, after which period it 
remains quiescent for a period and then slips its ]ast skin over its 
body, much in the same way as it has done in the previous moult- 
ings, and becomes a pale yellow soft pupa, which soon hardens 
and turns brown. Before completing this last change but one, the 
larva assumes a curious and rather beautiful appearance; it seems 
shrivelled and contracted in length, the tubercles approach close 
together, and both extremities are somewhat recurved ; the colour 
is of a vivid green, tipped on the tubercles and feet with a deep 
blue. So shrunken and lessened it seems as to suggest the idea of 
death, but the change into the pupa form soon assures us that all 
is according to nature. 
Tt not unfrequently happens that after beginning a cocoon the 
work seems to proceed irregularly and unequally, and the cocoon 
is then either abandoned or after much labour and pains turns out 
an abortion; sometimes the Jarva has been disturbed by the 
approach of other larva, endeavouring to eat up the leaf which he 
has selected; sometimes he begins badly, either on the wrong sur- 
face of the leaf, or on too small a portion of aleaf. In such cases, 
where it is evident that a mistake has been made, if the work has 
not gone very far it is best to remove the larva toa fresh and 
suitable leaf, where he will again commence ; if however much silk 
has been emitted, it will be better to take the larva away alto- 
gether, and place him in a paper cot, or piece of brown paper 
crumpled up, when he will generally spin a slender cocoon and 
go through his changes. 
After the cocoons are hardened, so as to stand a consider- 
able amount of pressure, they may be gathered if required ; 
to do this it is only necessary to cut the cable which attaches 
the cocoon to the leaf-stalk, leaving a sufficient base of cable to 
permit the threading-needle to be passed through it without in- 
volving the cocoon ; the cocoons may be placed in baskets and 
housed. ‘They would hang in safety all through the winter on the 
trees, but as most people desire to house and secure a crop as early 
as possible that they may estimate its value, so probably Ailan- 
thiculturists will seek an early moment to harvest their cocoons ; 
