6o6 
Journal of Agricultural Research 
Vol. XXVII, No. 8 
glandular structures in the floor of the mouth nor to the gizzard, the 
interior lining of which resembles parchment, making the presence of 
secretory glands improbable. 
EXPERIMENTAL DATA 
The method of preparing the enzym solutions was in accordance with 
those usually employed. The chicken was killed either by dislocating 
the neck or by decapitation, and the alimentary canal immediately re¬ 
moved. The crop was cut open, washed out with water, and, after being 
cut into small pieces, was ground in a mortar with sand and a little 
toluene to prevent putrefaction. The entire pancreas was ground in a 
similar manner with sand and toluene. The proventriculus and intestine 
were cut open, washed out with running water, and the mucous mem¬ 
branes scraped off and ground in a mortar with sand and toluene. 
The organs from three to six chickens were used in each of three ex¬ 
periments. In order to control more carefully the methods used in 
this investigation, the small intestines of five young rats were ex¬ 
amined in the same manner as were those of the chickens. The 
extracts in all cases were made by adding 75 to 125 cc. of water to 
the ground organs and allowing the mixture to stand at room temper¬ 
ature for one to three days, with occasional shaking. The mixture was 
then strained through cloth to remove the sand and larger pieces of the 
organs and the filtrate was made up to a definite volume, usually 100 or 
150 cc. The presence of lactase in the extracts was determined by 
adding to exactly 50 cc. portions of 4 per cent lactose solution, 25 cc. 
of the unheated extract in one case, and, as a control, 25 cc. of the 
boiled extract. Three cc. of toluene were added to each flask and 
the flasks corked and incubated at 36° to 38° C. for two to six days. 
After the period of incubation, the contents of the flasks were examined 
for monosaccharids by means of Barfoed’s copper acetate reagent. 
This test was made without previous precipitation of the proteins. 
The digested extracts were carefully filtered and the clear filtrates used. 
The procedure adopted consisted in adding 2 cc. portions of the boiled 
and unboiled digested filtrates to 5 cc. portions of the copper acetate re¬ 
agent and placing the resulting solutions in boiling water for exactly 
five minutes. The test was considered negative if no reduction was 
apparent during the five minutes boiling or during the three minutes 
after removal from the water bath. All tests were run in duplicate and 
the solutions containing the boiled and unboiled extracts were run side 
by side, at the same time and in exactly the same manner. The results 
obtained are summarized in Table I. 
