1. INTRODUCTION
9
eter in the environment. As Preyer pointed out in his "Elemente," a
physiological function should be considered in relation to a functioning
apparatus and to a material substrate, for instance, a vascular system
and liquids, a digestive system and aliments, a sensory system and a
perceptible phenomenon. The relationship was that of the blowing wind
and the windmill grinding the grain. In his comparative work directed
towards knowledge of the diversity of organisms, Preyer insists on the
idea that we should not compare embryonically concordant structures
(the homologous), but functionally concordant structures, the isodynamous parts functionally equivalent in spite of differences of morphology
and evolution. Preyer sought for a history of functions, and his series
is to be understood as a classification of physiological innovations, according to their growing complexity but without reference to phylogeny.
Thus, for example, he insisted on the importance of discovering transitions between the circulation of cytoplasmic granules and currents of
blood.
Comparative physiological studies have also provided valuable information on phylogeny. For instance, the morphologists studied the
transition of locomotion in Vertebrates, from aquatic to terrestrial life.
A study of the morphological evolution of pentadactylous appendages
with respect to transformations at the level of the skeletal apparatus
and of the muscular apparatus resulted. Comparative physiological
studies have, on the other hand, explained the complex mechanisms
controlling not only the movements of the limbs, but also the relation
of their position with the position of the organism itself. As Redfield
says: "The fact that the fish's fin is primarily an organ of equilibrium
rather than of locomotion is of the utmost importance, for it shows
that long before the problem of standing or running arose in the terrestrial vertebrate, the neurological mechanism for postural co-ordination was laid down in the paired appendage." As it is only natural,
morphologists and taxonomists in their comparative studies, have kept
as their fundamental concept the notion of homology, i.e., the community of origin, while comparative physiologists, primarily concerned
with the organism living in its natural ecological niche, have been
mainly interested in the accomplishments and inventions of organisms.
It is also quite natural that physiologists have gathered such valuable
information on the many ways through which the different organisms
solve the problem of their relation with a parameter of the medium.
II. The Comparative Point of View in Biochemistry
Thus, the great successes of experimental biology have led to
recognition of structural and functional similarities and diversities
among living organisms. A major contribution of the physical sciences
9
eter in the environment. As Preyer pointed out in his "Elemente," a
physiological function should be considered in relation to a functioning
apparatus and to a material substrate, for instance, a vascular system
and liquids, a digestive system and aliments, a sensory system and a
perceptible phenomenon. The relationship was that of the blowing wind
and the windmill grinding the grain. In his comparative work directed
towards knowledge of the diversity of organisms, Preyer insists on the
idea that we should not compare embryonically concordant structures
(the homologous), but functionally concordant structures, the isodynamous parts functionally equivalent in spite of differences of morphology
and evolution. Preyer sought for a history of functions, and his series
is to be understood as a classification of physiological innovations, according to their growing complexity but without reference to phylogeny.
Thus, for example, he insisted on the importance of discovering transitions between the circulation of cytoplasmic granules and currents of
blood.
Comparative physiological studies have also provided valuable information on phylogeny. For instance, the morphologists studied the
transition of locomotion in Vertebrates, from aquatic to terrestrial life.
A study of the morphological evolution of pentadactylous appendages
with respect to transformations at the level of the skeletal apparatus
and of the muscular apparatus resulted. Comparative physiological
studies have, on the other hand, explained the complex mechanisms
controlling not only the movements of the limbs, but also the relation
of their position with the position of the organism itself. As Redfield
says: "The fact that the fish's fin is primarily an organ of equilibrium
rather than of locomotion is of the utmost importance, for it shows
that long before the problem of standing or running arose in the terrestrial vertebrate, the neurological mechanism for postural co-ordination was laid down in the paired appendage." As it is only natural,
morphologists and taxonomists in their comparative studies, have kept
as their fundamental concept the notion of homology, i.e., the community of origin, while comparative physiologists, primarily concerned
with the organism living in its natural ecological niche, have been
mainly interested in the accomplishments and inventions of organisms.
It is also quite natural that physiologists have gathered such valuable
information on the many ways through which the different organisms
solve the problem of their relation with a parameter of the medium.
II. The Comparative Point of View in Biochemistry
Thus, the great successes of experimental biology have led to
recognition of structural and functional similarities and diversities
among living organisms. A major contribution of the physical sciences