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;
a definite line of forms? If it will do this from generation
to generation it is considered living matter ; if it will not then
it is regarded as inanimate matter, as matter containing no
life.
Digestion.
Digestion is performed by what are known as digestive
bodies, unorganized ferments or enzymes, these three terms
being synonymous in their use in this connection. Of these
there are a large number. In the animal or in man we have
the ptyalin of the saliva, the pepsin of the stomach, the pan-
creatin of the pancreas, and a large number of others in dif-
ferent parts of the alimentary tract, which meet the food arid
have their particular function in the digestion of different
foodstuffs along the line of the alimentary canal. In the
plant we have also a considerable number. One of the first
is diastase. A number of them have been isolated; perhaps
a great number yet remain to be discovered and isolated.
These three words, however, are intended to cover any and
all of these digestive bodies, the word enzyme being now
more frequently used, perhaps, than the others. In the
higher animals the food first meets with the ptyalin of the
saliva, which has a particular effect, the conversion of starch
into sugar being the principal one. In the stomach it meets
with the pepsin, or the gastric juice, which is formed by
the glands in the walls of the stomach, the peptic glands, and
thrown out to meet the food there, by which it is converted
into peptones. And then, in the alimentary tract, it meets
with these various other substances that continue the con-
version of different portions of food. The effect is to break
up the food, form a solution and change its chemical charac-
ter by its conversion into peptones ; the chemical form is not
the same. Then it is absorbed in the walls of the stomach
into the blood directly and by the glands in the walls of the
intestines into the lacteals, and by these two routes it passes
to the liver and to the lungs, and, meeting with the air in
the lungs and through the action of the liver, it is again
changed and loses its character as peptone, as lacteal fluid,
and passes then into the blood and is carried to the tissues
there again it is changed in its chemical characters, it is redi-
gested, as it were, and is woven into the protoplasm and into
76
a definite line of forms? If it will do this from generation
to generation it is considered living matter ; if it will not then
it is regarded as inanimate matter, as matter containing no
life.
Digestion.
Digestion is performed by what are known as digestive
bodies, unorganized ferments or enzymes, these three terms
being synonymous in their use in this connection. Of these
there are a large number. In the animal or in man we have
the ptyalin of the saliva, the pepsin of the stomach, the pan-
creatin of the pancreas, and a large number of others in dif-
ferent parts of the alimentary tract, which meet the food arid
have their particular function in the digestion of different
foodstuffs along the line of the alimentary canal. In the
plant we have also a considerable number. One of the first
is diastase. A number of them have been isolated; perhaps
a great number yet remain to be discovered and isolated.
These three words, however, are intended to cover any and
all of these digestive bodies, the word enzyme being now
more frequently used, perhaps, than the others. In the
higher animals the food first meets with the ptyalin of the
saliva, which has a particular effect, the conversion of starch
into sugar being the principal one. In the stomach it meets
with the pepsin, or the gastric juice, which is formed by
the glands in the walls of the stomach, the peptic glands, and
thrown out to meet the food there, by which it is converted
into peptones. And then, in the alimentary tract, it meets
with these various other substances that continue the con-
version of different portions of food. The effect is to break
up the food, form a solution and change its chemical charac-
ter by its conversion into peptones ; the chemical form is not
the same. Then it is absorbed in the walls of the stomach
into the blood directly and by the glands in the walls of the
intestines into the lacteals, and by these two routes it passes
to the liver and to the lungs, and, meeting with the air in
the lungs and through the action of the liver, it is again
changed and loses its character as peptone, as lacteal fluid,
and passes then into the blood and is carried to the tissues
there again it is changed in its chemical characters, it is redi-
gested, as it were, and is woven into the protoplasm and into
76
