December, ’18] YOUNG: PORTABLE INSECT ARY 479 
nailed together at right angles, this is held in place by a screw into 
each panel; extra ventilation may be had by allowing the battens to 
extend under the saddle boards, raising the latter a little from the 
panels. The front and back screens and door are of J x 3 in. pine, 
halved and fastened together at each union by two f-in. screws. 
The door is 6 ft. 2J in. x 2 ft. 9^ in. with one horizontal cross tie. 
The two front side screens are 6 ft. 2| in. on side next the door; 4 ft. 
1| in. base; 3 ft. in. on outside vertical edge; 4 ft. 4| in. on oblique 
edge, flush with the top of rafter, and 11J in. on top; each has one 
horizontal cross tie at the same height as the door. The triangular 
screen over the door is 4 ft. 8| in. at the base, and 3 ft. 3J in. on the 
oblique sides, which are also flush with the top of the rafter. The two 
back screens are 8 ft. 5 in. on their longest vertical, 3 ft. 1J in. on out¬ 
side vertical, 5 ft. 6 in. on base, 7 ft. 8 in. on the top oblique edge flush 
with the top of rafter, the joint at the abutting edges under the ridge is 
covered by a f x 2\ in. batten. 
The interior may be arranged to suit the needs of the investigation. 
We found that benches 30 in. wide and 28 in. from the bottom of the 
sill, along both sides and rear end, also a narrow hanging shelf 16 in. 
wide, set on a level with the top of side screen and supported by brack¬ 
ets fastened to each rafter, made a very convenient arrangement. The 
benches were of the heavier wallboard laid on a suitable frame. 
The approximate cost of this Insectary was as follows: Wallboard, 
$55; lumber and hardware, $25; paint and varnish, $20. A carpenter 
and one assistant should build this structure in six days. 
We have found this Insectary thoroughly practical, solving our prob¬ 
lem for maintaining normal climatic conditions under full control, which 
is a first requisite for the development of delicate experimental work. 
The writer is very grateful to Mr. A. F. Burgess, entomologist in 
charge, for enthusiastic support and encouragement, and to many of 
the assistants of the Bureau at the Gipsy Moth Laboratory for helpful 
suggestions. Among these special credit is due Mr. H. A. Preston for 
preparing photographs, Mr. Irving T. Guild for drafting plans, and to 
Mr. J. V. Schaffner, Jr., and E. R. Sturges who assisted in planning 
and construction work. 
A drawing showing the details of construction is reproduced as 
plate 17 and a blueprint can be furnished to anyone desiring to build 
an Insectary of this sort. 
