KERATINS. 



115 



Bodies occur in the animal kingdom which form to a certain extent 

 intermediate substances between coagulated protein and keratin. C. 

 TH. MORNER n has detected such a body (album&id) in the tracheal car- 

 tilage which forms a net-like trabecular tissue. This substance appears 

 to be related to the keratins on account of its solubilities and the quan- 

 tity of the sulphur (lead-blackening) it contains, while according to its 

 solubility in gastric juice it must stand close to the proteins. Another 

 substance, nearly like keratin, is the horny layer in the gizzard of birds. 

 According to J. HEDENIU^ this substance is insoluble in gastric or pan- 

 creatic juice, and acts quite like keratin. According to K. B. HOFMANN 

 and PREGL, 12 who call this substance koilin, it does not yield any cystine 

 on hydrolysis, or at least not a determinable quantity. According to 

 others the quantity of cystine is very small. BUCHTALA 13 obtained only 



1 Abderhalden and Wells, Zeitschr. f . physiol. Chem., 46. 



2 Buchtala, ibid., 52. 

 * Argiris, ibid., 54. 



4 Abderhalden and Voitinovici, ibid., 52. 

 6 Abderhalden and Le Count, ibid., 46. 



6 Abderhalden and Ebstein, ibid , 48. 



7 Korner, ibid., 34 and 42. 



8 Pregl, ibid., 56. 



9 Buchtala, ibid., 74. 



10 Abderhalden and Fuchs, Zeitschr. f . physiol. Chem., 57, have shown that the 

 same variety of keratin, on ageing of the horn structure, becomes somewhat poorer 

 in glutamic acid. 



11 See Maly's Jahresber., 18. 



12 Hedenius, Skand. Arch. f. Physiol., 3; Hofmann and Pregl, Zeitschr. f. physiol., 

 Chem., 52. 



13 Zeitschr. f . physiol. Chem., 69. 



