THE VITAMINES IN THE ANIMAL KINGDOM 89 



chickens in the laboratory to full growth depended upon the age of 

 the chickens used. He observed that the animals often failed to grow 

 on a normal diet, and he accordingly believed that this suppression 

 of growth had nothing to do with the vitamines, although his results 

 with white and with red (unpolished) rice, as compared with a normal 

 diet, were identical with ours. Drummond then tried to improve 

 the condition of the animals by giving them earth, sand and wood 

 chips, but without success. We showed later (248) that it was 

 possible to decrease the mortality of the animals and to improve 

 their general condition, by adding animal charcoal to the diet and 

 substituting milk for the drinking water. 



Buckner, Nollau and Kastle (249) demonstrated that young 

 chickens did not grow well on a diet poor in lysine, as compared to 

 one rich in lysine; the addition of butter was without effect. It is 

 not improbable that the diet rich in lysine possessed altogether better 

 nutritive value. Similar results with lysine were obtained by 

 Osborne and Mendel (250). In a later investigation, they (251) 

 occupied themselves with the problem of raising chickens in the 

 laboratory. They stated, in accord with our results, and in opposi- 

 tion to those of Drummond, that it is quite possible to raise young 

 chickens in cages. On a diet containing butter as a source of vita- 

 mine A, and an addition of filter paper, it was possible to raise some 

 several weeks old animals to normal size. Although most of the 

 animals suffered from weakness in the legs, the investigators believed 

 that as soon as all conditions for the growth of chickens were known, 

 it would be possible to conduct growth experiments similar to those 

 with rats. In these experiments, no green food was given and the 

 diet was thought to be completely carrotinoids-free, which was denied 

 by Palmer. Hart, Halpin and Steenbock (252) were of the opinion 

 that the disease of chickens mentioned above, designated "leg weak- 

 ness," could not be considered as an avitaminosis. Practical chicken 

 breeders attribute this disease to the close confinement, lack of green 

 food and over-eating. The above workers explained the condition 

 as being due to constipation and stated that the green food, because 

 of its vitamine content and cellulose, might have had a beneficial 

 influence on the constipation. They found indeed that green food 

 is not necessary, and that the same results could be obtained by giving 

 filter paper, dirt or animal charcoal instead; it was necessary to 

 mix these substances intimately with the diet. These additions 



