IMPORTATION AND HANDLING OF PARASITE MATERIAL, 157 
opening large enough to accommodate the head. No special pro- 
vision for ventilation is necessary, but it is necessary to construct 
the boxes of soft and absorbent wood in order to secure best results. 
This- will not only prevent too rapid evaporation, but superfluous 
moisture will first be absorbed and subsequently will evaporate. 
Tin boxes are wholly unsuitable and paper or pasteboard have never 
been at all satisfactory. 
Twigs with foliage should be included in each box, and these must 
be long enough to remain firmly braced in case the caterpillars eat 
the foliage. Some very bad results have followed the use of loose 
foliage, a practice which certain collectors have been persistent in 
following. 
The fewer the caterpillars included in each box the better the 
results. The number has gradually been reduced from 100 at first 
to 20 during the past few years. Undoubtedly 10 would be better 
yet, but not enough better to make the added expense an economy. 
The more nearly the caterpillars are ready to pupate when packed 
the better. If collected just a few days before pupation, they usually 
arrive in good shape, provided conditions otherwise are as they 
should be. 
Shipments by mail have generally been successful when the boxes 
were not smashed, as has sometimes happened, or when something 
else was not wrong. Shipments by express without cold storage 
have been equally successful when the boxes have been properly 
packed. As has been said, there is no need to provide for the ven- 
tilation of the interior of the box, but the exterior must be exposed 
to the air on at least one side to permit the evaporation of the mois- 
ture absorbed by the wood. Otherwise, as nearly always happens, 
when a part of the caterpillars or pupze die, they decompose, and as a 
result of their presence a similar fate usually overtakes the remainder. 
Some very large shipments were a complete loss in 1907, merely 
because a European agent, prevented by newly enforced postal 
regulations from making shipments by mail, packed the boxes tightly 
in large packing cases and forwarded them by express. When the 
lids were removed from these cases the sides of the boxes were found 
to be thoroughly damp, and the whole exhaled an ammoniacal odor 
so strong that it would seem of itself alone suflicient to destroy any 
ordinary form of insect life. 
Bundles of boxes wrapped in thick, glazed paper have almost invari- 
ably been received in bad condition. If the paper is soft and absorbent 
it is generally satisfactory. One collector wrapped several packages 
in a thick fabric composed of tarred paper strengthened by muslin, 
and the contents rotted. 
Cold storage in the case of shipments of this character would never 
have been either necessary or even desirable had it not been for the 
