1921] SPENCER—BRAZIL NUTS 269 
CORNMEAL AGAR.—This was prepared as recommended by 
SHEAR (26), except that the medium ready for filtration was poured 
into precipitation cones and autoclaved. After solidifying, the 
precipitated dirt at the apex of the inverted cone was removed and 
the clean agar melted and tubed. 
BRAZIL NUT AGAR.—Fifty grams of Brazil nut kernels which 
were free of, or easily freed from, their inner seed coats were 
ground in a nut grinder (a Russwin no. 1 Food Cutter was used), 
and steeped for one hour at from 58° to 60° C. in 1000 cc. of distilled 
water, counterpoised, and filtered. Fifteen grams of powdered 
or crude agar was added and the mixture boiled for ten minutes, 
counterpoised, poured into precipitation cones, and autoclaved at 
15 pounds for fifteen minutes. After solidification the agar was 
removed from the glass cone and placed on a clean sheet of paper. 
After removing the sediment the dirt-free agar was returned to the 
precipitation cone and again autoclaved. The resolidified agar 
cone was in two distinct layers, and the translucent layer was 
the one used. 
Nut pLucs.—It was found possible, by flaming a scalpel after 
each stroke, to cut out nut plugs of considerable size which were 
free from contamination. The kernels from which such plugs 
were to be cut were placed in a 2 to tooo solution of ic chlorid 
where they remained for thirty minutes. They were taken from 
the solution one at a time, held by one end between thumb and 
finger, and shaped by cutting away a thin layer with a sharp scalpel, 
flamed after each stroke. When the plug was finished it was cut 
off after placing it within the mouth of the reclining one-inch test 
tube. Nut plugs made in this way remained uncontaminated for 
several months. 
Nut strips.—Strips of nut meat, 50 uX5X1omm., were cut 
on a microtome and preserved in absolute alcohol. When used 
they were taken from the alcohol with sterilized forceps and placed 
in sterile water in a Petri dish. From this they were removed 
with a sterilized loop and placed in test tubes containing sterile 
water, as already described. 
AUTOCLAVED RICE.—This medium was made by placing two 
or three grams of rice and twice the volume of water in test tubes 
and autoclaving. 
