Vines . — The Proteases of Plants (III). 187 
may be taken as indicating the relative amount of ereptase in the individual 
cases. 
The results of fibrin-digestion, being so divergent, are more difficult 
to deal with. As I have already pointed out (see p. 184), these results fall 
naturally into two groups : those obtainable through a wide range of 
reaction from alkalinity to acidity ; those limited to acidity. It does not 
appear possible, at present, to attribute this marked divergence wholly to 
variations in the quantity of one and the same peptase : it seems to 
indicate difference in kind rather than in degree. It may be that there 
are in plants two varieties of peptases more adapted respectively to acid 
or to alkaline reaction. The decision must be left to more extended and 
exact experiments than I have yet been able to make. 
If it be admitted that two proteases or two groups of proteases exist 
in plants, the ascertained facts as to the distribution of the proteases in the 
vegetable kingdom may be succinctly stated in the following propositions : 
— all plants that have been examined contain ereptase: in some of these 
plants the ereptase has been found to be associated with a larger or smaller 
proportion of a peptase : in no plant has a peptase been found to exist 
unassociated with ereptase. 
List of Papers Referred to. 
1. Vines : Tryptophane in Proteolysis; Annals of Botany, vol. xvi, March, 1902, p. r. 
2. : Proteolytic Enzymes in Plants; ibid., vol. xvii, January, 1903, p. 237. 
3. : Proteolytic Enzymes in Plants (II); ibid., June, 1903, p. 597. 
4 . : Proteases of Plants; ibid., vol. xviii, April, 1904, p. 290. 
5. : Proteases of Plants (II) ; ibid., vol. xix, Jan. 1905, p. 149. 
6. Darwin : Insectivorous Plants, 1875, p. 301. 
7. Hooker : Address to the Department of Zoology and Botany of the British Association, Belfast 
Meeting, 1874. 
8. von Gorup-Besanez und Will: Fortgesetzte Beobachtungen liber peptonbildende Fermente 
im Pflanzenreiche; Sitzber. der physik.-med. Soc. zu Erlangen, 1876. 
9. von Gorup-Besanez : Weitere Beobachtungen liber diastatische und peptonbildende Fermente 
im Pflanzenreiche; ibid., 1875. 
10. Wurtz : Recherches cliniques et chimiques sur la papaine; Paris Medical, 1879. 
11. Martin: Papain-digestion; Journ. of Physiol., vol. v, 1884, p. 230. 
12. : The Nature of Papain and its Action on Vegetable Proteid ; ibid., vol. vi, 1885, p. 360. 
13. Green : On the Changes in the Proteids of Seeds which accompany Germination; Phil. Trans., 
vol. clxxviiiB, 1887, p. 58. 
14 . Chittenden: On the B'erments contained in the Juice of the Pine- Apple; Trans. Connecticut 
Acad., vol. viii, 1891, p. 26. 
15. Clautriau : La Digestion dans les urnes de Nepenthes ; Mem. couronnes, Acad. roy. de 
Belgique, vol. lix, 1900. 
16 . Vines : The Proteolytic Enzyme of Nepenthes (III) ; Annals of Botany, vol. xv, 1901, p. 569. 
17. Mendel and Underhill : Observations on the Digestion of Proteids with Papain ; Trans. 
Connecticut Acad., vol. xi, 1901, p. 13. 
18 . Weis: fetudes sur les enzymes proteolytiques de l’orge en germination; Comptes-rendus des 
travaux du Laboratoire de Carl sberg, vol. v, 1903, p. 133. 
P 
