THE FEED PROBLEM 263 



from various parts of the body; thus, hquids introduced into 

 the trachea or windpipe, as pilocarpin or morphin, will be 

 absorbed. Birds absorb solutions of strychnin very rapidly 

 when introduced by aid of a hypodermic syringe, either into 

 the muscular structures or into the abdominal cavity. The 

 author has repeatedly produced strychnia-poisoning in sixty 

 seconds by such injections. 



One grain of strychnin, given in a solution in warm water on 

 an empty crop, will produce its poisonous effect in a very 

 few minutes, showing absoi'ption from those mucous mem- 

 branes is rather rapid. 



Birds will absorb certain substances through the skin; thus, 

 it came to the notice of the author that on several occasions 

 birds which had been dusted with insect powder, containing 

 tobacco dust and other ingredients in considerable amounts, 

 became poisoned and some had died. The results of the poison 

 was invariably an acute hepatitis or inflammation of the liver. 



Absorption from the small intestines is from two sources — ■ 

 (1) through the villi into the lacteals, described above, and (2) 

 through the venous capillaries or minute blood-vessels lining 

 the mucous membrane. 



Urinary Excretion. — The kidneys eliminate nitrogenous 

 tissue waste, as well as certain salts and the excess water in the 

 body. 



The kidneys, two in number, are large in size and dark in 

 color, irregular in shape, and lay in excavations in the lumbo- 

 pelvic region. In the bird they are very large as compared 

 to the size of the bird. 



Urine is usually regarded as an excretion because it is of no 

 further use to the body. 



The waste material from the lymph-spaces throughout the 

 bodj'', being collected by capillaries and carried by the blood- 

 vessels to the heart, is laden with nitrogenous tissue waste. 

 From the heart the blood is pumped through the arterial sys- 

 tem to all parts of the body. The arterial blood, constantly 

 passing through the kidneys, carries a constant supply of the 

 nitrogenous tissue waste from which urea is manufactured by 

 the liver, and other salts are also removed and thus eliminated 

 from the body. 



