TASTE OF GRANIVOROUS BIRDS. 121 



as obtuse as if their edges and points had been 

 abraded by a grinding-stone. The longer the sphe- 

 rules continued in the stomach, the more minutely 

 were they triturated ; so that in a few hours they 

 were reduced to a mass of particles, not larger than 

 grains of sand. The rapidity also of this process 

 appears in some measure proportional to the size of 

 the animal. A wood-pigeon generally breaks them 

 less speedily than a chicken, a chicken than a capon, 

 but a goose the soonest of all. The reason is plain, 

 since the larger species have thicker and more power- 

 ful stomachs*.'' 



It appeared from these experiments that smooth 

 and blunt substances, though thus violently acted 

 upon, did not injure the texture of the stomach. 

 Spallanzani hence bethought him of trying what 

 effects would be produced by sharp and angular sub- 

 stances, and upon introducing into the gizzard of a 

 cock a piece of rough jagged glass, he found that in 

 the space of twenty-four hours, the angles were all 

 broken off, without having wounded or even scratched 

 any part of the stomach. When we take this into 

 account, therefore, we ought not to consider the sub- 

 sequent experiments of the Abbe so very cruel and 

 revolting as at first sight they must appear. For 

 the purpose, accordingly, of discovering the extent of 

 this singular power of the gizzard to break sharp 

 points without sustaining injury, " twelve strong tin 

 needles," says Spallanzani, " were firmly fixed in a 

 ball of lead, the points projecting about a quarter of 

 an inch from the surface. Thus armed, it was co- 

 vered with a case of paper and forced down the throat 

 of a turkey. The bird retained it for a day and a 

 half without showing the least symptoms of uneasi- 

 ness. Why the stomach should have received no 

 injury from so horrid an instrument I cannot explain : 

 * Dissertations, i. 14. 



