CASES USED IN TRANSPORTING PARASITES. 35 
was of such height that the top of the young trees placed thereon 
would approximate or slightly exceed the height of the hedge. (See 
PL VIII, figs. 2, 3.) 
Potted plants were arranged on this platform immediately preced- 
ing the emergence of the brood of the white fly in September. The 
awning was then so extended as completely to cover the hedge except 
at the side on which the plants were placed. This procedure not only 
protected the foliage from the sun but so shaded the hedge that when 
the white flies became active in the morning and evening they would 
come in contact with the potted trees, in their flight toward the light, 
and thus be more likely to oviposit thereon than upon the hedge itself. 
All fresh and tender foliage was removed from the hedge before 
emergence of the white fly took place so as to render its foliage less 
attractive than that of the potted plants. As a result the flies ovi- 
posited freely on the young plants and a gross infestation was thereby 
secured. 
The plants were continued in this position after infestation in order 
to afford natural conditions for the action of parasites. About the time 
white-fly eggs commenced to hatch, parasites could be seen running 
about the young plants, and later it was found that the percentage 
of parasitism on the young trees was equally as great as had been 
seen on the infested hedge at any period during the observations. 
It was now the middle of October and, believing that all conditions 
at that time were most opportune for success in carrying through the 
parasite to America in good condition, the writer commenced boxing 
the plants on October 18 preparatory to shipment. 
Cases Used in Transporting Parasites. 
When tender plants are shipped long distances, as from one country 
to another, a specially made crate called a Wardian case has been 
used with marked success. These cases much resemble miniature 
greenhouses, being constructed of heavy wood throughout with the 
exception of the top, which is made of glass. The cases are perfectly 
tight except for two small holes at the top, which afford a slight ex- 
change of air with the outside. Plants contained in these cases go 
great distances without watering. The writer's attention was called 
to this case by Mr. C. L. Marlatt, assistant chief of this bureau, and 
by Mr. David Fairchild, in charge of plant introductions in the Bureau 
of Plant Industry of this department. Request for one of these cases 
was made to the Government Botanical Garden, Calcutta, and in due 
time a sample case was constructed and shipped to Lahore. These 
Wardian cases are used for seedling plants, and consequently are low- 
topped. It was found that in order to utilize this type of case for our 
insect-infested plants it would be necessary to make a number of altera- 
tions. This was done and the completed case as used for transporting 
