192 HABITS OF BIRDS. 



stance, when just secreted it most probably very 

 soon coagulates into a granulated white curd ; for in 

 such a form, I have always found it in the crop, and 

 if an old pigeon is killed just as the young ones are 

 hatching, the crop will be found as above described, 

 and in its cavity pieces of white curd mixed with 

 some of the common food of the pigeon, such as 

 barley, beans, &c. If we allow either of the parents 

 to feed the young, its crop, when examined, will be 

 discovered to contain the same curdled substance, 

 which passes thence into the stomach, where it is to 

 be digested. 



u The young pigeon is fed for some time with 

 this substance only, and about the third day, some of 

 the common food is found mingled with it ; and as 

 the pigeon grows older, the proportion of common 

 food is increased ; so that by the time it is seven, 

 eight, or nine days old, the secretion of the curd 

 ceases in the old ones, and of course no more will be 

 found in the crop of the young. It is a curious fact, 

 that the parent pigeon has at first the power to 

 throw up this curd without any mixture of common 

 food, although afterwards both are thrown up ac- 

 cording to the proportion required for the young 

 ones. I have called this substance curd, not as 

 being literally so, but as resembling that more than 

 any thing 1 know : it may, however, have a greater 

 resemblance to curd, than we are perhaps aware of ; 

 for neither this secretion, nor curd from which the 

 whey has been pressed, seem to contain any sugar, 

 and do not run into the acetous fermentation. The 

 property of coagulating is confined to the substance 

 itself, as it produces no such effect when mixed with 

 milk. This secretion in the pigeon, like all other 

 animal substances, becomes putrid by standing, 

 though not so readily as either blood or meat, it 



