RICE DIET. 181 



III. EXPERIMENTS ON PIFTY-SIX FOWLS. 



Our experiments were begTin to determine the effects of various Phil- 

 ippine rices on fowls and to use the knowledge thus acquired in the 

 selection of a proper rice for issue to the native troops (Philippine 

 Scouts). As they progressed, several additional experiments were in- 

 stituted to throw light on some doubtful points observed in the original 

 series, such as the relation of loss of weight and of inanition to multiple 

 neuritis. 



The fowls were kept separately in cages 5 feet by 5 feet, made of wire netting 

 and wood; the floor, ceiling, and two sides being of pine boards, tongued and 

 grooved, and the two remaining sides of wire netting with 2-inch meshes. A 

 perch was placed across a corner of each cage about 20 inches from the floor. 

 The cages were arranged in two separate structures each having eight cages, 

 four below and four above. The roof was double with a large ventilating space 

 between the two layers to render the conditions in the upper tier equal to those 

 below. Figure 1 shows them very well. A high board fence around the yard 

 prevented passers by from feeding the fowls. Clean water in enameled cups 

 and a small amount of sterile gravel were kept in each cage. A run, 24 by 38 

 feet, inclosed by wire netting, adjoined the cages and in it were kept such extra 

 fowls as were not in actual use. 



During the course of the experiments six fowls developed infectious con- 

 junctivitis which caused the death of five. From the clinical appearances we 

 concluded that they were suffering from the so-called avian diphtheria which we 

 do not consider to bear any relationship to human diphtheria. (21) Two other 

 fowls also had the disease, accompanied by marked nose and throat symptoms. 

 When any signs of this disease appeared, the infected fowls were promptly isolated 

 and not used again for experiment, even if recovery took place. In Tables III 

 and IV those having avian diphtheria are specifically referred to. Great care 

 was taken to eliminate the possibility of this disease being the cause of death 

 or of neuritis in the fowls undergoing experiment. 



Tlie sciatic nerves of all fowls dying during the experiments were placed, as 

 soon as possible after death, in a 1 per cent osmic acid solution and sub- 

 sequently were examined microscopically after being teased out in glycerine. 

 The teasing was done with great care to avoid damaging structures which were 

 really normal and thereby giving an appearance of slight degeneration. For 

 controls . the nerves of seventeen healthy chickens were examined by the same 

 method. None of them presented the appearances of degeneration which were 

 found in the fowls that clinically showed symptoms of neuritis. 



Our birds were not especially selected as to breed, being the mixed varieties 

 commonly seen in the Philippines, but were carefully inspected for soundness. 

 Only cocks about three- fourths groA\m were accepted. 



The experiments, covering a period of nine months, are given below. 

 They are divided into four groups and fifteen classes, graphically ar- 

 ranged in Tables III and lY. 



GROUP A. TWENTY-NINE FOWLS SUBSISTING ON POLISHED RICE. 



In this group of experiments two kinds of polished rice were used; 

 a Philippine Macan rice, purchased in a native shop, and the Saigon 

 variety furnished by the Subsistence Department of the Army, the 



102362 2 



