8
MARCEL FLORKIN AND HOWARD S. MASON
definition of life, holding as purely incidental the existence of plants,
algae, mollusks, fishes, mammals, or bacteria. Life is not an abstract
conceptual system but manifests itself in the same organism through
such deeply different biochemical systems as a liver cell and an epidermal cell and through such biochemically different organisms as a
cockroach and an oaktree. Biochemistry also hopes to bring its contribution to the understanding of this infinite diversity: "infinite" being
the right adjective as, in biochemical as well as in other respects, each
living organism is a new reality.
If it is true that the cell theory and the theory of evolution reinforced the Unitarian trend of physiology, it also, in limited quarters,
called attention to the consideration of diversity. This kind of emphasis
had already been present in the writings of such outstanding naturalists
as Geoffrey St.-Hilaire and Milne-Edwards. The study of physiological
diversity was greatly enhanced by the foundation by Anton Dohrn, at
the Naples Zoological Station, of a physiological laboratory. As far
back as 1875, Dohrn, in an open letter to Von Siebold [Z. wiss. Zool.
25, 457 (1875)] underlines the fact that a theory of descendance, based
only on a collection of data provided by comparative anatomy and by
comparative embryology, brings light only on one face of the problem
and is only one of the factors to be taken into consideration. "Den
anderen bildet das Studium der Lebenweise und vergleichenden
Physiologie," as Dohrn writes. This appeal was heard by Preyer who,
in his "Elemente der allgemeinen Physiologie," published in 1883, tried
to introduce physiological considerations into the study of evolutionary
problems, a tendency which was immediately eclipsed by the success of
Verworn's "Allgemeine Physiologie," written as we have stated, according to a Unitarian tendency.
Anton Dohrn felt it impossible to adhere to this. In 1867, in a letter
to Haeckel reproduced in his biography by Theodor Heuss (the former
president of the German Republic), Dohrn clearly expressed his viewpoint on the necessary studies of comparative physiology to the benefit
of the progress of phylogenetic problems: "Wie konnte aus diesen so
beschaffenen Organen der Vorfahren dies so ganz anders beschaffender
Nachkommen hervorgehen? Die Kette der allmählichen Umwandlungen
muss ich erschliessen an der Hand physiologischer Hypothesen—und
wie sollen diese Hypothesen einigen Wert besitzen, solange die wirklich
vorhandenen Funktionen all der verschiedener Meerestiere uns so unbekannt bleiben, wie sie jetzt sind?" Since the beginning of the present
century, comparative physiology has collected a great amount of information making clear many aspects of the mechanism of this or that
organism and of the relation of the organism to its environment.
Physiologists are used to studying an organism in relation to one param-
MARCEL FLORKIN AND HOWARD S. MASON
definition of life, holding as purely incidental the existence of plants,
algae, mollusks, fishes, mammals, or bacteria. Life is not an abstract
conceptual system but manifests itself in the same organism through
such deeply different biochemical systems as a liver cell and an epidermal cell and through such biochemically different organisms as a
cockroach and an oaktree. Biochemistry also hopes to bring its contribution to the understanding of this infinite diversity: "infinite" being
the right adjective as, in biochemical as well as in other respects, each
living organism is a new reality.
If it is true that the cell theory and the theory of evolution reinforced the Unitarian trend of physiology, it also, in limited quarters,
called attention to the consideration of diversity. This kind of emphasis
had already been present in the writings of such outstanding naturalists
as Geoffrey St.-Hilaire and Milne-Edwards. The study of physiological
diversity was greatly enhanced by the foundation by Anton Dohrn, at
the Naples Zoological Station, of a physiological laboratory. As far
back as 1875, Dohrn, in an open letter to Von Siebold [Z. wiss. Zool.
25, 457 (1875)] underlines the fact that a theory of descendance, based
only on a collection of data provided by comparative anatomy and by
comparative embryology, brings light only on one face of the problem
and is only one of the factors to be taken into consideration. "Den
anderen bildet das Studium der Lebenweise und vergleichenden
Physiologie," as Dohrn writes. This appeal was heard by Preyer who,
in his "Elemente der allgemeinen Physiologie," published in 1883, tried
to introduce physiological considerations into the study of evolutionary
problems, a tendency which was immediately eclipsed by the success of
Verworn's "Allgemeine Physiologie," written as we have stated, according to a Unitarian tendency.
Anton Dohrn felt it impossible to adhere to this. In 1867, in a letter
to Haeckel reproduced in his biography by Theodor Heuss (the former
president of the German Republic), Dohrn clearly expressed his viewpoint on the necessary studies of comparative physiology to the benefit
of the progress of phylogenetic problems: "Wie konnte aus diesen so
beschaffenen Organen der Vorfahren dies so ganz anders beschaffender
Nachkommen hervorgehen? Die Kette der allmählichen Umwandlungen
muss ich erschliessen an der Hand physiologischer Hypothesen—und
wie sollen diese Hypothesen einigen Wert besitzen, solange die wirklich
vorhandenen Funktionen all der verschiedener Meerestiere uns so unbekannt bleiben, wie sie jetzt sind?" Since the beginning of the present
century, comparative physiology has collected a great amount of information making clear many aspects of the mechanism of this or that
organism and of the relation of the organism to its environment.
Physiologists are used to studying an organism in relation to one param-