TWENTIETH CENTURY EMBRYOLOGICAL CONCEPTS
31
immunological phenomenon. As a matter of fact, the significance of
immunological interpretations of developmental specificity was recognized very early for the case of fertilization by Lillie (1919), in work
which was of the greatest importance because, along with those of Child
and J. Loeb cited above, his was one of the strongest voices earlier in
this century to argue for the investigation of developmental phenomena
according to physiological as well as cytological principles. There were
others, too, whose interest in immunology as a developmental phenomenon long antedated the current flare of enthusiasm. Studies of tissue
specificity in transplantations, begun during the first World War by L.
Loeb (summarized in full, 1945), were interpreted on the basis of compatibility between like and like, and incompatibility between unlike and
unlike, in an immunological framework, and these ideas probably fed into
the newly developing embryological concepts to a degree that is rarely
acknowledged. The supposedly new embryology of the mid-20th century
is thus highly obligated to Leo as well as to his brother Jacques Loeb.
Yet while investigation of the field in which embryology and immunology overlap has not, as was earlier the case for conventional nuclear genetics, suffered a long delaying action at the level of study of
visible inclusions, nonetheless, after an early start (see the work of
Boucek, 1927, 1928, suggested by Nicholas), it is only now showing a
rapid spurt of progress (Cooper, 1946, 1948, 1950; Ebert, 1950, 1952,
1954; Irwin, 1949, 1955; Schechtman, 1947, 1952, 1955; GluecksohnWaelsch, 1954; Brambell et al., 1951; Brambell, 1954). Since it relates
problems of developmental specificity to those of cellular affinity and disaffinity at one level, to those of hereditary factors at another, and finally
to protein and other molecular systems at still another, it shows, just past
the middle of the century, promise of serving for a time at least a useful
synthesizing function.
It is clearly apparent, however, from much that has been said before,
that the immunological approach has not been the only avenue followed
by 20th century embryology down (or up?) towards the molecule. It
is one of the curiosities of almost all of the embryological studies of the
century that they have followed convergent paths leading in this direction. In fact, the embryology of the whole century has been so centrally
reliant on molecular explanations that it seems almost justifiable to inquire whether, because perhaps of the recondite nature of the phenomena
to be explained, embryologists may not have been for longer than other
biological specialists cognizant of the possibilities of interpretation at the
molecular level. Much of the work cited above in this essay has been
mentioned as instrumental in leading towards molecular embryology:
31
immunological phenomenon. As a matter of fact, the significance of
immunological interpretations of developmental specificity was recognized very early for the case of fertilization by Lillie (1919), in work
which was of the greatest importance because, along with those of Child
and J. Loeb cited above, his was one of the strongest voices earlier in
this century to argue for the investigation of developmental phenomena
according to physiological as well as cytological principles. There were
others, too, whose interest in immunology as a developmental phenomenon long antedated the current flare of enthusiasm. Studies of tissue
specificity in transplantations, begun during the first World War by L.
Loeb (summarized in full, 1945), were interpreted on the basis of compatibility between like and like, and incompatibility between unlike and
unlike, in an immunological framework, and these ideas probably fed into
the newly developing embryological concepts to a degree that is rarely
acknowledged. The supposedly new embryology of the mid-20th century
is thus highly obligated to Leo as well as to his brother Jacques Loeb.
Yet while investigation of the field in which embryology and immunology overlap has not, as was earlier the case for conventional nuclear genetics, suffered a long delaying action at the level of study of
visible inclusions, nonetheless, after an early start (see the work of
Boucek, 1927, 1928, suggested by Nicholas), it is only now showing a
rapid spurt of progress (Cooper, 1946, 1948, 1950; Ebert, 1950, 1952,
1954; Irwin, 1949, 1955; Schechtman, 1947, 1952, 1955; GluecksohnWaelsch, 1954; Brambell et al., 1951; Brambell, 1954). Since it relates
problems of developmental specificity to those of cellular affinity and disaffinity at one level, to those of hereditary factors at another, and finally
to protein and other molecular systems at still another, it shows, just past
the middle of the century, promise of serving for a time at least a useful
synthesizing function.
It is clearly apparent, however, from much that has been said before,
that the immunological approach has not been the only avenue followed
by 20th century embryology down (or up?) towards the molecule. It
is one of the curiosities of almost all of the embryological studies of the
century that they have followed convergent paths leading in this direction. In fact, the embryology of the whole century has been so centrally
reliant on molecular explanations that it seems almost justifiable to inquire whether, because perhaps of the recondite nature of the phenomena
to be explained, embryologists may not have been for longer than other
biological specialists cognizant of the possibilities of interpretation at the
molecular level. Much of the work cited above in this essay has been
mentioned as instrumental in leading towards molecular embryology: