102 



THE VITAMINES 



A further phenomenon, common to both forms of beriberi in 

 pigeons, is the loss in weight, which is apparent before the onset of 

 the symptoms. This loss, amounting to from 20 to 45 per cent of the - 

 original weight, occurs always in pigeons fed on rice, according to our 

 experience. The loss in weight is apparent whether the animal is 

 fed forcibly or not. Results to the contrary are due to the fact that 

 the pigeons, chiefly because of the paralysis of the muscles of the 

 crop, are unable to empty it. On post mortem, the crop is tightly 

 packed with rice, weighing about 100 grams, which ordinarily would 

 have been calculated as body weight. It cannot be emphasized 

 sufficiently that in experimental beriberi, following a strictly managed 



400 



350 

 300 

 250 

 ZOO 



no 



100 



FIG. 17. DROP IN WEIGHT OF PIGEONS FED ON 30 GRAMS POLISHED RICE DAILY 



diet, death ensues in 100 per cent of the cases. Theiler, Green and 

 Viljoen (278) have observed that starving pigeons, only on water, 

 may show spontaneous cures. This behavior was explained by the 

 mobilization of the vitamine in the tissues. The tissues are catabo- 

 lized more rapidly during starvation and therefore a greater supply 

 of vitamine may suddenly be made available for the animal. If rice 

 feeding is continued death must eventually ensue. The question of 

 malnutrition in beriberi was also taken up by Lumie're (279). 



Besides chickens and pigeons, beriberi has also been described in 

 other birds, which might sometimes also be of practical importance. 

 For instance, Merklen (280) described a disease in 3 or 4 weeks old 

 ducks manifesting itself in symptoms of cramps, paralysis of the legs 



