G. F. Barker—Physiological Chemistry. 53 
thus far held on this subject, the author states that his experi- 
ments sustain Pavy’s view, that the amyloid matter is not 
changed into sugar during life, Hence, it becomes necessary 
to account for the disappearance of this ‘substance and to show 
what its function really is in the animal economy. In the 
opinion of the author, the amyloid substance is “on its way 
upward toward the more exalted or complex animal princi- 
ples ;” and he accordingly suggests three points to be inves- 
tigated : 1st, The chemical and physiological relation of amy- 
loid substance, not only in the liver but also in other tissues. 
2d, The comparison of portal ard hepatic blood with each 
other, and with arterial and venous blood from other parts of 
the body. 3d, The relation which the different functions of 
the liver bear to each other. The last of these is the most im- 
portant, since, if it be true that the fibrin and albumin of portal 
blood disappear i in the liver, forming the amyloid substance, and 
at the same time only a trace of nitr ogen is excreted in the bile, 
__ then we may infer that this nitrogen issues in the hepatic blood 
united to amyloid substance as a new nitrogenous principle, 
_ which is the protoplasm, from which according to Bernard, or- 
_ ganic evolution is to be accomplished. McDonnell then calls at- 
tention to the occurrence of the amyloid substance in the foe 
placental cells, and also in their tissues, as shown by Bernard 
and Rouget; and remarks that these tissues are “so i impregna- 
ted with Sane d substance, that it appears to be the formative 
material from which these tissues are evolved,” being related 
to their growth and development, as starch is to that of vege- 
table tissues. He observes that the horny tissues contain it 
plentifully ; enough for a chemical examination may ob- 
tained from a single hoof of a foetal calf, and from the mus- 
PCE ESTE eT 
Wey AiR BN ae Sa gE Ue Eb a 
30 cede 
, n 
_ 20 to 50 per cent may be extracted, Being convinced of the 
truth of Pavy’s view that amyloid substance is not normally 
changed into glucose, and having himself proved the accuracy 
of the facts stated by Bernard and Rouget concerning the rela- 
tions of this substance to the foetal tissues, McDonnell asks “may 
not the liver do for the adult what the foetal tissues do in the 
embryo ? may not this great organ form with the help of the 
—— substance secreted in its cells, a nitrogenous compound, 
just as the muscles of the foetus convert the amyloid substance 
contained in them into the highly nitrogenous material o 
muscular tissue ? May not the amyloid substance of the liver 
be the basis of an azotized protoplasma forming a constituent 
of the blood of the adult animal, as the amyloid substance of 
muscle is the basis of the material from which the evolution 
of muscular tissue is accomplished ?” The author is disposed 
