10
JANE Μ. OPPENHEIMER
(Boveri, 1901), and he introduced as its explanation the concept of the
gradient, "Gefälle" (Boveri, 1910), evoking at least on the basis of
qualitative evidence the possibility of a quantitative distribution of some
entity or entities as appertaining to the structural and functional differences in the egg along the axis joining its two poles.
The question of the extent to which Child and Spemann were individually obligated to Boveri is an interesting and a puzzling one.
Child in his fullest treatment of his interpretations freely acknowledges
Boveri's priority in postulating the idea of a gradient (Child, 1941,
p. 700):
"The frequency with which the suggestion that physiological
polarity is a gradation or gradient pattern of some sort or a stratification of substances has appeared in biological literature is both interesting and significant. A polar pattern of this sort was suggested
for the sea-urchin egg and later for the egg of Ascaris by Boveri. . . .
In many papers on regeneration Morgan postulated gradations of
formative substances and also suggested gradation of tension."
Child himself first used the term axial gradient, to the best of my
knowledge, in the title of a paper, published in April, 1911, which included no reference to Boveri. Boveri's 1910 paper was published not
in a regular periodical but in the "Festschrift" for Richard Hertwig's
sixtieth birthday; it was already cited by Child in The Process of Reproduction in Organisms, published in June, 1912. In a rather general
paper on the physiological gradients Child (1928) refers not only to
Boveri, but also to Morgan, in 1904 and 1905, and to Sachs in 1880 as
having conceived of polarity "in terms of the flow or gradation of formative substances" (Child, 1928, p. 448).
It is one of the obstacles to an approach to certainty in intellectual
history that the influence of one idea or pattern of ideas on the development of another is not always accurately indicated by references either
in texts or bibliographies, a fact which Spemann himself well recognized;
and he discussed it specifically with reference to the influence of Boveri
on the concepts forming the basis of the present disquisition. Spemann
was quite cognizant of the kinship of some of Child's notions to Boveri's
ideas, and commented that Child's "conception of a 'dominant region*
corresponds very nearly to Boveri's 'region of preference'," (Spemann,
1938, p. 321), a region of predilection at the vegetal pole of the egg
postulated as influencing the development of the rest.
7
But he was not
7
The common philosophical background leading to concepts of dominance in
both embryology and genetics at this time has not to the best of my knowledge
JANE Μ. OPPENHEIMER
(Boveri, 1901), and he introduced as its explanation the concept of the
gradient, "Gefälle" (Boveri, 1910), evoking at least on the basis of
qualitative evidence the possibility of a quantitative distribution of some
entity or entities as appertaining to the structural and functional differences in the egg along the axis joining its two poles.
The question of the extent to which Child and Spemann were individually obligated to Boveri is an interesting and a puzzling one.
Child in his fullest treatment of his interpretations freely acknowledges
Boveri's priority in postulating the idea of a gradient (Child, 1941,
p. 700):
"The frequency with which the suggestion that physiological
polarity is a gradation or gradient pattern of some sort or a stratification of substances has appeared in biological literature is both interesting and significant. A polar pattern of this sort was suggested
for the sea-urchin egg and later for the egg of Ascaris by Boveri. . . .
In many papers on regeneration Morgan postulated gradations of
formative substances and also suggested gradation of tension."
Child himself first used the term axial gradient, to the best of my
knowledge, in the title of a paper, published in April, 1911, which included no reference to Boveri. Boveri's 1910 paper was published not
in a regular periodical but in the "Festschrift" for Richard Hertwig's
sixtieth birthday; it was already cited by Child in The Process of Reproduction in Organisms, published in June, 1912. In a rather general
paper on the physiological gradients Child (1928) refers not only to
Boveri, but also to Morgan, in 1904 and 1905, and to Sachs in 1880 as
having conceived of polarity "in terms of the flow or gradation of formative substances" (Child, 1928, p. 448).
It is one of the obstacles to an approach to certainty in intellectual
history that the influence of one idea or pattern of ideas on the development of another is not always accurately indicated by references either
in texts or bibliographies, a fact which Spemann himself well recognized;
and he discussed it specifically with reference to the influence of Boveri
on the concepts forming the basis of the present disquisition. Spemann
was quite cognizant of the kinship of some of Child's notions to Boveri's
ideas, and commented that Child's "conception of a 'dominant region*
corresponds very nearly to Boveri's 'region of preference'," (Spemann,
1938, p. 321), a region of predilection at the vegetal pole of the egg
postulated as influencing the development of the rest.
7
But he was not
7
The common philosophical background leading to concepts of dominance in
both embryology and genetics at this time has not to the best of my knowledge