6 BULLETIN 193^ U. S. DEPARTMENT OF AGEICULTURE. 



During prolonged cases of lead poisoning, the alimentary tract 

 exhibited several changes that were characteristic of the trouble. In 

 normal birds the ventriculus, or gizzard, and the crop may be 

 crammed with food, but the proventriculus, or glandular portion of 

 the stomach, is empty. In cases of lead poisoning from eating shot 

 the appetite for food is greatly increased, while the gizzard seems 

 slow in action, and observations indicate that the great muscles in 

 its walls are more or less paralyzed. In these birds the proven- 

 triculus and the lower portion of the oesophagus are greatly dis- 

 tended with food, so that they form a mass larger than the gizzard 

 itself and have their walls stretched to the utmost. (PL II, fig. 1.) 



The pads lining the inside of the gizzard often appear more or less 

 corroded and slough easily, while gravel may work up into the lower 

 portion of the proventriculus, a condition that is unknown in the 

 healthy animal. The contents of the gizzard were usually stained 

 green. Occasionally this color extended through the food contained 

 in the lower part of the proventriculus. 



Generally the shot were found on washing out the matter con- 

 tained in the gizzard, though a few were located in the lower end 

 of the proventriculus. The usual number of shot in one stomach 

 was 15 to 40. The largest number of pellets taken from one bird was 

 76, found in the gizzard of a mallard secured near the mouth of the 

 Bear River, Utah. In September, 1916, during routine laboratory 

 work, 28 mallards and 10 pintails that had died from lead poisoning 

 were examined. From the stomachs of these 38 birds 939 shot were 

 recovered, an average of a fraction less than 25 each. Wliere shot 

 have been in the gizzard for a considerable time they are much 

 worn, and in many cases are ground down to flattened disks by the 

 action of the stomach muscles and the trituration with gravel. 



The intestine may be irritated, or may be nearly free from dis- 

 tended capillaries. Observations on this point are uncertain, as the 

 birds examined were from regions where the waters frequented con- 

 tain irritant salts, usualh^ in quantities sufficient to bring about a 

 certain amount of congestion in the capillaries of the intestinal walls 

 of the waterfowl. Where many shot are in the stomach the walls 

 of the small intestine may be discolored, and in nearly every case 

 there is a deposit of lead on the inner walls of the caeca. This de- 

 posit is most pronounced in the distal third of these blind guts, but 

 may extend for their entire length. The caecum appears lead colored 

 from without, but when slit and examined its inner walls are found 

 to be blackish. The gall bladder is always full and may be much 

 distended. In one individual examined the gall bladder measured 

 30 mm. long by 12 mm. in diameter. The bile is very dark green, 

 and after death this color may spread slowly until it has stained the 



