THE DIGESTIVE TRACT. 601 



these animals, peculiar granular bodies, usually accumulated 

 along the apices, but occurring also in the vacuoles of the epi- 

 thelia, or in goblet-like formations produced by the epithelia. A 

 few guinea-pigs which I examined in New- York exhibited the 

 same formations formations that do not occur in the intes- 

 tines of other herbivorous animals I had examined. These are 

 clusters composed of a pale granular mass, containing a num- 

 ber of green or greenish-yellow granules, with a high degree of 

 refraction j I also found isolated granules of various sizes. (See 

 Fig. 257.) 



The differences in the number, the color, and appearance of these bodies 

 were found to vary according to the following conditions : Embryos of 

 guinea-pigs, examined a few days before birth, had no corpuscles in their 

 villi. Newly born guinea-pigs, one to two hours after birth, showed no cor- 

 puscles ; but sixteen to twenty-four hours after birth, the animals being fed 

 with oats, the villi showed a number of yellowish-green bodies, with fine 

 granules. All the animals of a more advanced age exhibited the green cor- 

 puscles in the villi. The color was evidently dependent on the vegetable 

 food. After feeding with fresh blades of grass a light chlorophyll-green was 

 seen, and a light, pure yellow color appeared after feeding with the flowers of 

 leontodon taraxacum ; a dim yellowish-green was observed after a continued 

 administration of vegetables. When the stomach remained filled with food 

 the contents, from the cardia toward the pylorus, showed all shades of green 

 to yellow-green ; this green shade remained for a month or a month and a 

 half after the fresh vegetable diet had been stopped and amylaceous food had 

 been exclusively administered. A light yellow-green color was mainly 

 observed in autumn and after feeding with straw. If blue aniline was mixed 

 with the food the granules assumed a dark bluish-green. After administra- 

 tion of starchy food for one and a half to two months, the granules were col- 

 orless and the animals died, evidently from starvation; it was only under 

 these conditions that the stomach was found empty. The granules were 

 largest after feeding with the young leaves of plants, and smallest after 

 administration of dry vegetable food or oats. The age of the animals had no 

 influence upon the color and shape of the granules. In two instances I found 

 such granules in mesenteric ganglia also. 



Unquestionably the granules are chlorophyll granules, and 

 their coloring matter is chlorophyll ; for it can be extracted with 

 alcohol, and assumes a yellowish-brown color when preserved in 

 chromic acid. Very probably these bodies are vegetable bio- 

 plasson, having left the shell of cellulose. But in what way did 

 they penetrate into the stroma or central lymph-vessel of the 

 villus? 



In guinea-pigs several hours old I found villi containing three 

 or four corpuscles in their axes, the uppermost of which was 

 located in a craterif orm depression in the middle of the apex. Not 



