*368 ELDON W. SANFORD 
secretion of the crop cells, somewhat on the secretion which flows 
in from the stomach, and partly on the secretion which the saliv- 
ary glands have poured in. It is certain that in the crop the neu- 
tral or alkaline secretion of the salivary glands acts on carbo- 
hydrates and renders them soluble, as Jordan and others have 
established. 
To obtain information as to the reaction of the secretion of 
the epithelium of the crop alone, I removed the crops from ten 
animals and placed them in normal salt solution, then slit them 
longitudinally, and carefully washed out the contents. The 
crops were then ground fine in a mortar with 10 ce. of clean salt 
solution, and the mixture left two hours to make an extract. 
The mixture was then filtered and the filtrate tested. This fil- 
trate proved to be neutral to phenol-phthaleine and alkaline to 
litmus. This indicated definitely that the normal secretion of 
the crop is slightly alkaline. 
Though the crop secretion is alkaline, I did not always find 
in my feeding experiments that the contents of the crop were 
alkaline after fatty food had been eaten for certain periods. 
Nile blue sulphate is a good indicator in work with fats, for it 
stains fats blue and fatty acids red. I fed an animal a large 
amount of a paste of olive oil and sugar, stained bright blue with 
the indicator stain. Three days later, on dissection, the whole 
content of the anterior crop proved to be deep red, while the epi- 
thelium was blue. The presence of red fatty acid in the lumen 
indicated that some agency, probably an enzyme, had acted onthe 
fat to produce fatty acid. This process was more definitely ex- 
plained by a series of feeding experiments in which powdered 
litmus was mixed with the food eaten by the animals. If, when 
the crop was subsequently opened, the contents were observed 
to be red, they were considered to be acid in reaction; if blue, 
alkaline. . 
Miall and Denny, Ramme, Jordan and Biedermann have 
maintained that the acid secretion found in the crop after feeding 
was derived entirely from the stomach and coeca, which had 
flowed from them through the gizzard into the crop. Their idea 
is that a large part of the digestion occurs in the crop, but that 
