180 Proceedings of Royal Society of Edinburgh. [sess. 
The presence of albumins in the secretion was also confirmed by 
the reactions recommended by Dr R. Palm (Zeitschrift fur Analy- 
tisclie Chemie , vol. xxvi. part i.). 
7. The secretion contains leucin and tyrosin, no doubt produced 
by the metamorphoses of certain albuminous substances. 
We know from Professor Poster’s Physiology (4th ed. p. 438), 
that “one result of the action of the pancreatic juice is the forma- 
tion of considerable quantities of leucin and tyrosin.” Leucin and 
tyrosin are “ dehydrated in a true liver , forming a series of cyan- 
hydrins or cyan-alcohols attached to a benzene nucleus, which then 
pass into the circulation ” — (Latham). 
8. The principal mineral ingredient found in the ashes (inciner- 
ated at a low temperature) of the so-called “liver” of Carcinus was 
sodium carbonate. In the ash of a vertebrate liver the chief mineral 
constituents are potassium and phosphoric acid. 
9. The soluble zymase (ferment) secreted by the organ in ques- 
tion was extracted according to the Wittich-Kistiakowsky method 
(Pfliiger’s Arcliio fur Physiologie , vol. ix. pp. 438-459). The 
isolated ferment converts fibrin into leucin (a-amidocaproic 
acid, C 6 H 13 N0 2 ) and tyrosin (paraoxyphenylamidopropionic acid, 
C 9 H u NO s ). 
10. No glycocholic and taurocholic acids could be detected by 
the Pettenkofer and other tests. 
11. No glycogen was found in the organ or its secretion. 
12. The secretion has no action upon cellulose. 
13. By using the methods adopted by M. Zaleski (Zeitschrift fur 
Physiologische Chemie , vol. x. pp. 453-502) for ascertaining the 
presence of ferrous, ferric, and ferrosoferric compounds in a true 
liver, the author could not detect the presence of iron in the organ 
or its secretion. 
From these reactions the conclusion to be drawn is, that the so- 
called “ liver” of Carcinus moenas is pancreatic in function, i.e. f its 
secretion is more like the secretion of the pancreas of the Vertebrata 
than those of a true liver. 
Some biologists look upon the vertebrate liver, pancreas, and 
salivary glands as differentiated bodies of an original pancreas of the 
Invertebrata. But have not many forms of the lower animals 
