122 



THE PROTEIN SUBSTANCES. 



The elementary composition of certain of the bodies belonging to 

 this group is as follows : 1 



c 

 Conchiolin (from the shells of pinna) . . 52 . 70 



(from snail eggs) 50 . 92 



Spongin 46 . 50 



" 48.75 



Cornein 48 . 96 



Fibroin 48.23 



" 48.30 



Sericin 44 . 32 



" 44.50 



Spongin forms the chief mass of the ordinary sponge. It dissolves with 

 difficulty in concentrated mineral acids but dissolves with readiness in caustic 

 alkalies. It does not give the MILLON reaction or ADAMKIEWICZ'S. It gives 

 no gelatin. On hydrolysis spongin yields considerable glycocoll 13.9 per cent, 

 glutamic acid 18.1 per cent, leucine 7.5 per cent, proline 6.3 per cent, lysin 

 3-4 per cent, and arginine 5.6 per cent. 2 Tyrosine and phenylalanine could 

 not be detected. After HUNDESHAGEN had shown the occurrence of iodine 

 and bromine in organic combination in different sponges and designated the albu- 

 moid containing iodine, iodospongin, HARNACK 3 later isolated from the ordinary 

 sponge, by cleavage with mineral acids, an iodospongin which contained about 

 9 per cent iodine and 4.5 per cent sulphur. STRAUSS 4 has obtained sponginoses 

 of various kinds from spongin by dilute acids. The heterosponginose contained 

 the greater part of the iodine and sulphur, while the deuterosponginose contained 

 the carbohydrate groups. Iodospongin is considered as a derivative of the 

 heterosponginose. Conchiolin is found in the shells of mussels and snails arid 

 also in the eggshells of these animals. It yields, according to WETZEL,* glycocoll, 

 leucine, and abundance of tyrosine. The quantity of diamino-nitrogen amounts 

 to 8.7 per cent and the amide nitrogen 3.47 per cent (from the shell of pinna). 

 The Byssus contains a substance, closely related to conchiolin, which is soluble 

 with difficulty. According to ABDERHALDEN 6 it yields considerable glycocoll 

 and tyrosine and also alanine, aspartic acid and very large amounts of proline. 



Cornein is the name given to the substance of the axial system of 

 certain Anthozoa. The substance occurring in the groups of Gorgonia 

 and Antipathes has been called gorgonin by C. MORNER 7 and differs from 

 the pennatulin of the Pennatulidese by the latter being readily soluble 

 in pepsin -hydrochloric acid. The cleavage products have not been care- 

 fully studied; one of the crystalline products, called cornicrystalline by 



1 Krukenberg, Ber. d. d. chem. Gesellsch., 17 and 18, and Zeitschr. f. Biologie, 22; 

 Croockewitt, Annal. d. Chem. u. Pharm., 48; Posselt, ibid., 45; Cramer, Journ. f. 

 prakt. Chem., 96; Vignon, Compt. rend., 115; Wetzel, Zeitschr. f. physiol. Chem., 29 

 and Centralbl. f. Physiol., 13, 113; Bondi, Zeitschr. f. physiol. Chem., 34. 



2 Abderhalden and Strauss, Zeitschr. f. physiol. Chem., 48; Kossel and Kutscher, 

 ibid., 31, 20o. 



3 Zeitschr. f. physiol. Chem., 24; Hundeshagen, Maly's Jahresber., 25, 394; see 

 also L. Scott, Biochem. Zeitschr., 1. 



4 Biochem. Centralbl., ?. 



J Zeitschr. f. physiol. Chem. 29, and Centralbl. f. Physiol., 13, 113. 



Zeitschr. f. physiol. Chem., 55. 



7 Zeitschr. f . physiol. Chem., 51 and 55. 



