26 REPORT OF THE SECRETARY. 



and larger in birds than in other animals. The blood lost during 

 starvation was rapidly restored with vegetable diet, its solid constitu- 

 ents, however, were less with the latter than with animal food. The 

 proportion between the blood corpuscles and liquor sanguinis was not 

 altered, though the saline constituents were diminished with a vegeta- 

 ble diet. In many instances the shells of the terrapins became softer, 

 and the effect of a change of diet was also exhibited in the digestive 

 organs. The small intestines were enlarged, and a much greater 

 amount of water was thrown into the circulation than in the case of 

 the use of animal food, and hence water, holding albumen in solution, 

 accumulated in the cellular tissues and serous cavities. The urine 

 was rendered more abundant, and its specific gravity and chemical re- 

 lations changed. 



The remarkable difference which is known to exist between the 

 digestive apparatus of carnivorous and graminivorous animals, is ex- 

 hibited most strikingly in the comparative length of the alimentary 

 canal ; for example, that of the common cat is five feet and a third in 

 length, while that of the sheep is eighty-eight feet. 



Fishes afford the best means of studying the development of the 

 pancreas ; the permanent forms which it assumes in them being but 

 the transient condition of its development during the growth of the 

 higher animals. This organ is found in carnivorous fishes, reptiles, 

 and mammalia, to be relatively much larger than in frugivorous and 

 graminivorous animals. The pancreas of warm-blooded is larger than 

 that of cold-blooded carnivora. The opinion advanced by Bernard is 

 sustained, viz : that the office of the pancreas is to prepare fatty mat- 

 ter for absorption. The shape and appearance of the liver vary 

 greatly. The former appears to be determined by that of the animal 

 and its abdominal cavity. The size also varies, and on this point a 

 series of results are given as to the ratio of its weight to that of the 

 whole body. The livers of all animals, cold or warm-blooded, as far 

 as the author's observations have extended, yield grape sugar, which 

 passes into the circulation and disappears in the lungs so long as nor- 

 mal respiration is maintained. In cold-blooded animals it is never a 

 healthy constituent of the urine ; if a supply of oxygen be cut off, it 

 is accumulated in the blood and eliminated by the kidneys. The 

 spleen, which is absent from all invertebrate animals, varies in form, 

 size, and position in different reptiles. In the mammalia it is large, 

 and presents manifold diversities of form. It is smallest in birds and 

 ophidians, and largest in fishes and mammals. It appears to be an 



