418 



CHEMISTRY OF THE PROTEIDS 



CHAP. 



readily digested by pepsin and by trypsin, which is difficult to under- 

 stand because it contains much phenylalanin and but little tyrosin. It 

 is not attacked by erepsin. 1 



3. The Histone from the Red Blood Corpuscles of the Goose 



This histone was the first to be discovered. Kossel 2 found and 

 described it, and also prepared it by dissociating its nucleic acid 

 salt. The percentage composition of Kossel's preparations varied, but 

 the N-content was high, being over 18 per cent, while the amount of 

 sulphur only amounted to 0'5 per cent. 



This histone is quite distinct from globin, as it is contained in the 

 nuclei, while haemoglobin is only present in the cell-plasm. 



4. The Histones from the Testes of Fishes and of other Animals 



Miescher 3 found in the unripe testes of the salmon in combina- 

 tion with nucleic acid a body which he regarded as an albumose, but 

 which probably belongs to the histones. Bang 4 obtained from the 

 immature testes of the mackerel a compound which greatly resembles 

 Miescher's albumose and which he calls scombron. But the affix 

 -on had better be reserved for the peptone-like decomposition products 

 of the protamins (Cohnheim). Both histones by maturing are changed 

 into the protamins : salmin and scombrin. But the spermatozoa of 

 other fish, such as the cod (Gadus morrhua 5 ) and Lota vulgaris, 6 

 as well as those of the sea-urchin (Arbacia pustulosa 7 ), even when 

 mature, contain not protamins but histones. 



The following analyses are available : 



The dissociation-products of the Lota- and Gadus-histones are 

 given on p. 74, Nos. 38 and 39. Here also the high arginin- 



1 0. Cohnheim, ibid. 35. 134 (1902). 



2 A. Kossel, ibid. 8. 511 (1884). 



3 F. Miescher aiid 0. Schmiedeberg, Arch. f. experiment. Path. u. Pharmak. 37. 1 

 (1896). 



4 J. Bang, Zeitschr. f. physiol. Chem. 27. 463 (1899). 



5 A. Kossel and F. Kutscher, ibid. 31. 165 (1900). 



6 K. Ehrstrora, ibid. 32. 350 (1900). 7 A. Mathews, ibid. 23. 399 (1897). 



