THE VITAMINES IN THE ANIMAL KINGDOM 87 



above two vitamines, with or without vitamine C, only one died. 

 Out of six animals getting A-vitamine but not C-vitamine, all died 

 in about 155 days. Out of five animals receiving vitamine B, with 

 or without C, four survived for 250 days. 



Accordingly, B-vitamine is necessary for the maintenance of 

 grown frogs, although the symptoms were noticeable only after six 

 months, while the C-vitamine appears to exert no influence on the 

 animals. 



BIRDS 



Chickens 



As stated in the historical part, Eijkman (I.e. 50) and Grijns (I.e. 

 52) were the first to experiment with chickens. It was particularly 

 noted that Eijkman, by feeding chickens with the food discarded by 

 a beriberi hospital, observed that they developed a disease which he 

 called "Polyneuritis gallinarum." Eijkman soon found that other 

 foodstuffs, like sago and starch, could also bring on this disease. 



Normal nutrition of chickens. We shall first consider the normal 

 dietary requirements of the chicken. One who has tried to raise 

 young chickens in the laboratory knows the great difficulties that 

 have to be dealt with. The first attempt in this direction was made 

 by the author (244) who investigated the influence of various kinds of 

 foods on the growth of experimental tumors. In spite of the great 

 eagerness with which the chickens ate the food, growth ceased and 

 they developed a characteristic disease of the legs; the toes lost their 

 vigor and were bent. Very often it was noticeable that the beak was 

 not closed properly, and the animals died because of their inability 

 to pick up food. The eyes were frequently closed, and the chickens 

 suffered from a disease which gradually led to complete blindness, 

 and which would have been regarded to-day as ophthalmia. A 

 change in the diet was not enough to better conditions since the 

 animals were already receiving quite a variety of food. An attempt 

 was made to feed the chickens with live grub-Worms, and for a time 

 the floors of the cages were covered with grass and earth, which was 

 frequently renewed. We believed then that the wooden floors had 

 some pathological effect on the legs of the animals. However, all 

 these measures were of no avail and the birds became sick, showing 

 symptoms which we then attributed to rickets. On this basis, we 

 used cod liver oil as a therapeutic measure. As the figures below 

 indicate, a young chicken could maintain itself for eight months on 



