I’lrr~mtu(1992), 13, 91-94
Classics Revisited: Joseph Needham: ‘Chemical Embryology’- Cambridge 193 1 HOBE SCHRÖDER Universitäts Krankenhaus Hambuq German,y
Eppendmj,’ .tlartinistrassr
52,
21?00
‘Chemical Embryology’ was published in 1931 by Cambridge University Press and the MacMillan Company, a reprint appeared in 1963 (Hafner Publishing Corp.). CE w-as Needham’s third major monograph (after ‘Man a Machine’, 1927, and ‘The Skeptical Biologist’, 1929), the work of a then 3 1 -year-old biochemist that above al1 was written for ‘the increase of knowledge itself’, presenting ‘. . . the physico-chemical history of embryo development, from the egg-cel1 to the loosing of the individual into the activity of the postnatal life’. As in his first two books, he deliberately intervened in the struggle between ‘vitalism’ and ‘mechanism’ raking the standpoint of ‘neo-mechanism as a theory for chemical embryology’ which regards ‘the mechanistic view of the world as a legitimate methodological distortion, capable of application to any phenomenon whatever, and possessing no value at al1 as a metaphysical doctrine’. CE was designed to support this view (that no transcendency is needed to understand the events of the immanent world) by collecting and structuring ‘al1 the facts that are known about the physico-chemical aspects of embryonic development’. Embryology, with its strong linkages to ‘Weltanschauung’ and emotions stil1 relevant today (cf. the anti-abortionist debate), must have been a special challenge for the young scientist. Needham felt that ‘. . . physico-chemical embryology has . . . arrived at a stage immediately prior to birth’, and he was willing to play the role of the ‘skilful obstetrician’, a plain understatement for he had in fact established ‘chemical embryology as a branch of exact biology’ (Yells, 1932). In the country of science Needham laid out the County ot Embryology, complete with its own history, its cities and pathways to neighboring communities, ready to grow and prosper. This was a formidable task which is reflected in the size and structnre of CE. The book consists of three volumes with a total of 2120 pages, 532 text figures and 11 plates, more than 4500 citations and 5 1 pages of index. (In a recent book on Reproductive Physiology, a total of about 25 000 references is given- distributed among 99 authors). It seems that CE was wel1 received in the English speaking scientific community but, curiously, 1 have been unable to find a book review of CE in major German journals of anatomy and embryology of the 1930s. This bias is stil1 apparent if we look at the national distribution of the 146 papers in natura1 sciences that have cited CE in the period from 1974 to 1991 (SCISEARCH). Ninety-seven authors were working in the UK, Canada and the USA; 13 in India and, seven in New Zealand and Australia. From continental Europe came 20 quotations, including seven from Germany. (Here CE could only be located in one of 0143~4004/92/010091
+ 04 $05.00/0
@) 1992 Raillière Tindall
1.ttl
Placenta (1992), Vol. 13
92
approximately 500 libraries). The others are from Africa (l), the Far East (5), South America (1) and the USSR (2). The average number of quotations was 9 per year in the late 1970s and 6 per year in the late 1980s. Two citations were from 91 -both covering experimental work on the same animal to which CE devotes so many pages, the avian embryo. It is interesting to look at the specialty (as judged from the journal titles) the quoting scientists belong to: biology (zoology) 42; morphology ten; biochemistry/physiology 25; medicine nine; science in genera1 (incl. history) 15; others 45. So, evidently, CE stil1 has to say something to scientists experimenting more that 40 years later. We might compare the 146 citations within the last 28 per cent of CE’s life span with books of similar scope: ‘Human Embryology’ (Hamilton, Boyd and Mossman, 1st edition, 1945) was cited by 686 papers, and ‘Medical Embryology’ (Langman, 1st edition, 1963) by 48 1, but CE was never brought up to date, and everything stops at 1930. This is a heavy blow. Needham surveyed the County of Embryology, and its main landscape, roads and points of interest. CE is divided into three parts- 1: the Theory of Chemical Embryology (2 per cent), 11: the Origins of Chemical Embryology (ll.4 per cent, subdivided into Embryology in Antiquity, E. from Galen to Renaissance, and E. in the 17th and 18th century) and 111: Genera1 Chemical Embryology. Part 11 was expanded into ‘A History of Embryology’ published in 1934 (Cambridge). Since 1974 it has been cited 20 times in natura1 science journals. Table 1 gives the titles of the 24 sections of Part 111. The Epilegomena (3.4 per cent) deals with genera1 problems like ‘Biochemistry and Morphogenesis’ (no Watson-Crick model!) and the Theory of (chemical) Recapitulation, resulting in 32 ‘rules’ as a ‘Provisional Generalisation for Chemical Embryology’. Chemical Embryology starts strictly with the fertilized egg-cell, so no information on gametogenesis, functions of the genital tracts, fertilization itself etc. are provided, but the knowledge about al1 vertebrates (and in some case about insect as well) is given instead. Tahle 1.
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. ll. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24.
The Unfertilized Egg as a Physico-chemical System On Increase in Size and Weight On Increase in Complexity and Organization The Respiration and Heat-production of the Embryo Biophysical Phenomenon in Ontogenesis Genera1 Metabolism of the Embryo The Energetics and Energy-sources of Embryonic Development Carbohydrate Metabolism Protein hletabolism The Metabolism of Nucleins and Nitrogenous Eutractives Fat Metabolism The Metabolism of lipoids, Sterols, Cycloses, Phosphorus and Sulphur Inorganic hletabolism Enzymes in Ontogenesis Hormones in Ontogenesis Vitamins in Ontogenesis Pigments in Ontogenesis Resistance in Susceptibility in Embryonic Life Serology and Immunology in Embryonic Life Biochemistry of the Placenta Biochemistry of the Placenta1 Barrier Biochemistry of the Amniotic and Allantoic Liquids Blood and Tissue Chemistry of the Embryo Hatching and Birth
(8.4) (10.4) (4.4) (9.8) (3.7) (6.4) (3.2) (3.3) (5.5) (1) (2.1) I:)5) (2.8) (1.4) (0.5) (0.9) (3.8) (0.7) (1.7) ;::;; (1.8) (1.1)
93 Tabk 2. Section 20.1 20.2 20.3 20.4 20.5 20.6 20.7
20: Introduction General Metabolism of the Placenta Placenta1 Respiration Nitroeen Metabolism of the Placenta Carbihydrate Metabolism of the Placenta Fat and Lipoid hletabolism of the Placenta Placenta1 Enzymes
Section 21. 21.1 The Autonomu of the Foetal Blood 21.2 Evolution of the Placenta 21.3 I listotrophe and Haemotrophe 21.4 hlesonephros and Placenta 21.5 Colostrum and Placenta 21.6 Placenta1 Transmission and hlolecular Size 21.7 Qualitative Eqeriments on Placenta1 Permeabili21.8 ‘l’he Passage of Hormones 21.9 Factors goveming Placenta1 Transmission 2 1.10 Quantitative Experiments on the Passage of Nitrogenous Substances 2 1.11 Quantitative Experiments on the Passage of Phosphorus, Fats, and Sterols 2 1.12 Quantitative Experiments on the Passage of Carbohydrates 2 1.13 Quantitative Experiments on the Passage of Ash 2 1.14 The Passage of Enzymes 21. IS The Unequal Balance of Blood Constituents
A closer look into the placenta and the list of subheadings of Sections 20 and 21 is appropriate (Table 2). ‘Biochemistry of the Placenta’ is mostly concerned with the composition of placenta1 tissues and its changes during pregnancy. The search for substances that initiate uterine contractions and labour was already on-acetylcholine and arginine being the favorite candidates in those days. Quite a few placentae (human and others) had been perfused to study placenta1 metabolism, not transfer. The latter problem is addressed in ‘The Biochemistry ofthe Placenta1 Barrier’ which starts with the caveat stil1 worthwhile that ‘. . . work , . . on placenta1 permeability requires to be arranged according to the animal . . . and . . . to the time of gestation’. Grosser’s scheme is discussed in connection with placenta1 evolution, and an intriguing relation between the maternal-fetal ‘distance’ (in terms ofplacental layers) and the morphometric appearance of the transient mesonephros is revealed. As to the nature of the placenta1 barrier it is clearly understood that it must have passive (‘filter’) and more complicated (‘secretory’) functions. The importante of molecular size is recognized, and from the higher concentrations of ‘free amino-acid nitrogen’ in the fetal circulation a ‘regulatory mechanism in the placenta’ is deduced for amino acids which ‘the cells seem to take out of the maternal blood and to “hand on”‘. In the four subsections on ‘Quantitatil-e l_xperiments on . . ,’tables are given that summarize the concentrations of many substances in maternal and fetal blood. It seems somewhat baffling that the quantitative concepts ot permeability (Teorell, 1935) or of clearance are not addressed, even though the significance of the blood streams (including their mutual arrangements) is seen and the necessar)clements were known (Fick, 18.55; Cohnstein and Zuntz, 1884; CE’s tables even give umbilical av-differences for lactate and glucose). Lf71at is the impact of ‘Chemical Embryology’? Firstly, it laid the foundation of a branch ot science, and therefore sustains, to some extent, the activity of al1 ofus who read this journal. It
94
Placenta (1992), Vol. 13
furthermore added momentum to the already rolling bal1 of ‘mechanism’ and thus influenced the course and development of natura1 science generally. Is it worthwhile (for the non-historian) to look into ‘Chemical Embryology’ nowadays (if you can get hold of a copy)? CE certainly is much more than a gigantic old mine that stil1 contains precieus stones. It is rather a guide and map leading through the many aspects of embryology, showing beautiful and surprising outlooks you may never have expected. My favorite trails are the ‘Origin of Chemical Embryology’ which is simply delightful to read, and Section 3, ‘On Increase in Complex@ and Organization’. It provides the framework for many of the sections to come, and it may wel1 be that the reader wil1 find here the roots of his or her own specialty. True, CE also has some flaws. For example, no uniform typography was adopted for the many equations in Section 2 which sometimes leaves the reader helpless and some of the formulae are simply wrong, but this adds a human touch to an otherwise almost super-human mind. This applies also to many spicy and sharp-tongued remarks on the essence of the publications discussed. In summary, you should definitely try ‘Chemical Embryology’. Finally some words on Joseph Needham (Spengler, 1977). Born in 1900 he was educated as a schoolboy at Oundle in ‘practica1 scientific laboratory werk’. He started with biology at Cambridge, but soon moved to biochemistry by joining F. G. Hopkins. In 1924, Caius College elected him as fellow, later the Royal Society also accepted him and his wife Dorothy as fellows. Having started so outstandingly in natura1 sciences he slowly drifted ‘eastward’ focusing his interests more and more on the history of China. His work culminated in the monumental multi-volume ‘Science and Civilisation in China’ (Cambridge, since 1954). To embryology his power of compilation and contemplation was lost. It may help to understand his intellectual capacities if we know (Temple, 1990) that he is fluent in at least eight languages, and that he has a photographic memory allowing him, for example, to proof read his manuscripts ‘in his head’. Joseph Needham is stil1 alive.
REFERENCES Cohnstein, J. & Zuntz, N. (1884) Pjüger? Archir, 34, 173. Fick, A. (1855) Ann. Physik. Chem, 94, 59. Spengler, T. (1977) Wissenschaftlicher Universalismus. Über Bedeuhmg und Besonderheit Wissenschaft. Suhrkamp Verlag, FrankfurtIMain. Temple, R. (1990) Al1 in his head (boek reviews). Yaiature, 348, 59 1. Teorell, T. (1935) Proceedingsof the Socie[yJi>rExperimental BiologyandMedicine, 33, 282. Wells, F. E. (1932) New books and publications. Anatomical Record, 51.
der chinesischen
Classics Revisited: Joseph Needham: ‘Chemical Embryology’- Cambridge 193 1 HOBE SCHRÖDER Universitäts Krankenhaus Hambuq German,y
Eppendmj,’ .tlartinistrassr
52,
21?00
‘Chemical Embryology’ was published in 1931 by Cambridge University Press and the MacMillan Company, a reprint appeared in 1963 (Hafner Publishing Corp.). CE w-as Needham’s third major monograph (after ‘Man a Machine’, 1927, and ‘The Skeptical Biologist’, 1929), the work of a then 3 1 -year-old biochemist that above al1 was written for ‘the increase of knowledge itself’, presenting ‘. . . the physico-chemical history of embryo development, from the egg-cel1 to the loosing of the individual into the activity of the postnatal life’. As in his first two books, he deliberately intervened in the struggle between ‘vitalism’ and ‘mechanism’ raking the standpoint of ‘neo-mechanism as a theory for chemical embryology’ which regards ‘the mechanistic view of the world as a legitimate methodological distortion, capable of application to any phenomenon whatever, and possessing no value at al1 as a metaphysical doctrine’. CE was designed to support this view (that no transcendency is needed to understand the events of the immanent world) by collecting and structuring ‘al1 the facts that are known about the physico-chemical aspects of embryonic development’. Embryology, with its strong linkages to ‘Weltanschauung’ and emotions stil1 relevant today (cf. the anti-abortionist debate), must have been a special challenge for the young scientist. Needham felt that ‘. . . physico-chemical embryology has . . . arrived at a stage immediately prior to birth’, and he was willing to play the role of the ‘skilful obstetrician’, a plain understatement for he had in fact established ‘chemical embryology as a branch of exact biology’ (Yells, 1932). In the country of science Needham laid out the County ot Embryology, complete with its own history, its cities and pathways to neighboring communities, ready to grow and prosper. This was a formidable task which is reflected in the size and structnre of CE. The book consists of three volumes with a total of 2120 pages, 532 text figures and 11 plates, more than 4500 citations and 5 1 pages of index. (In a recent book on Reproductive Physiology, a total of about 25 000 references is given- distributed among 99 authors). It seems that CE was wel1 received in the English speaking scientific community but, curiously, 1 have been unable to find a book review of CE in major German journals of anatomy and embryology of the 1930s. This bias is stil1 apparent if we look at the national distribution of the 146 papers in natura1 sciences that have cited CE in the period from 1974 to 1991 (SCISEARCH). Ninety-seven authors were working in the UK, Canada and the USA; 13 in India and, seven in New Zealand and Australia. From continental Europe came 20 quotations, including seven from Germany. (Here CE could only be located in one of 0143~4004/92/010091
+ 04 $05.00/0
@) 1992 Raillière Tindall
1.ttl
Placenta (1992), Vol. 13
92
approximately 500 libraries). The others are from Africa (l), the Far East (5), South America (1) and the USSR (2). The average number of quotations was 9 per year in the late 1970s and 6 per year in the late 1980s. Two citations were from 91 -both covering experimental work on the same animal to which CE devotes so many pages, the avian embryo. It is interesting to look at the specialty (as judged from the journal titles) the quoting scientists belong to: biology (zoology) 42; morphology ten; biochemistry/physiology 25; medicine nine; science in genera1 (incl. history) 15; others 45. So, evidently, CE stil1 has to say something to scientists experimenting more that 40 years later. We might compare the 146 citations within the last 28 per cent of CE’s life span with books of similar scope: ‘Human Embryology’ (Hamilton, Boyd and Mossman, 1st edition, 1945) was cited by 686 papers, and ‘Medical Embryology’ (Langman, 1st edition, 1963) by 48 1, but CE was never brought up to date, and everything stops at 1930. This is a heavy blow. Needham surveyed the County of Embryology, and its main landscape, roads and points of interest. CE is divided into three parts- 1: the Theory of Chemical Embryology (2 per cent), 11: the Origins of Chemical Embryology (ll.4 per cent, subdivided into Embryology in Antiquity, E. from Galen to Renaissance, and E. in the 17th and 18th century) and 111: Genera1 Chemical Embryology. Part 11 was expanded into ‘A History of Embryology’ published in 1934 (Cambridge). Since 1974 it has been cited 20 times in natura1 science journals. Table 1 gives the titles of the 24 sections of Part 111. The Epilegomena (3.4 per cent) deals with genera1 problems like ‘Biochemistry and Morphogenesis’ (no Watson-Crick model!) and the Theory of (chemical) Recapitulation, resulting in 32 ‘rules’ as a ‘Provisional Generalisation for Chemical Embryology’. Chemical Embryology starts strictly with the fertilized egg-cell, so no information on gametogenesis, functions of the genital tracts, fertilization itself etc. are provided, but the knowledge about al1 vertebrates (and in some case about insect as well) is given instead. Tahle 1.
1. 2. 3. 4. 5. 6. 7. 8. 9. 10. ll. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24.
The Unfertilized Egg as a Physico-chemical System On Increase in Size and Weight On Increase in Complexity and Organization The Respiration and Heat-production of the Embryo Biophysical Phenomenon in Ontogenesis Genera1 Metabolism of the Embryo The Energetics and Energy-sources of Embryonic Development Carbohydrate Metabolism Protein hletabolism The Metabolism of Nucleins and Nitrogenous Eutractives Fat Metabolism The Metabolism of lipoids, Sterols, Cycloses, Phosphorus and Sulphur Inorganic hletabolism Enzymes in Ontogenesis Hormones in Ontogenesis Vitamins in Ontogenesis Pigments in Ontogenesis Resistance in Susceptibility in Embryonic Life Serology and Immunology in Embryonic Life Biochemistry of the Placenta Biochemistry of the Placenta1 Barrier Biochemistry of the Amniotic and Allantoic Liquids Blood and Tissue Chemistry of the Embryo Hatching and Birth
(8.4) (10.4) (4.4) (9.8) (3.7) (6.4) (3.2) (3.3) (5.5) (1) (2.1) I:)5) (2.8) (1.4) (0.5) (0.9) (3.8) (0.7) (1.7) ;::;; (1.8) (1.1)
93 Tabk 2. Section 20.1 20.2 20.3 20.4 20.5 20.6 20.7
20: Introduction General Metabolism of the Placenta Placenta1 Respiration Nitroeen Metabolism of the Placenta Carbihydrate Metabolism of the Placenta Fat and Lipoid hletabolism of the Placenta Placenta1 Enzymes
Section 21. 21.1 The Autonomu of the Foetal Blood 21.2 Evolution of the Placenta 21.3 I listotrophe and Haemotrophe 21.4 hlesonephros and Placenta 21.5 Colostrum and Placenta 21.6 Placenta1 Transmission and hlolecular Size 21.7 Qualitative Eqeriments on Placenta1 Permeabili21.8 ‘l’he Passage of Hormones 21.9 Factors goveming Placenta1 Transmission 2 1.10 Quantitative Experiments on the Passage of Nitrogenous Substances 2 1.11 Quantitative Experiments on the Passage of Phosphorus, Fats, and Sterols 2 1.12 Quantitative Experiments on the Passage of Carbohydrates 2 1.13 Quantitative Experiments on the Passage of Ash 2 1.14 The Passage of Enzymes 21. IS The Unequal Balance of Blood Constituents
A closer look into the placenta and the list of subheadings of Sections 20 and 21 is appropriate (Table 2). ‘Biochemistry of the Placenta’ is mostly concerned with the composition of placenta1 tissues and its changes during pregnancy. The search for substances that initiate uterine contractions and labour was already on-acetylcholine and arginine being the favorite candidates in those days. Quite a few placentae (human and others) had been perfused to study placenta1 metabolism, not transfer. The latter problem is addressed in ‘The Biochemistry ofthe Placenta1 Barrier’ which starts with the caveat stil1 worthwhile that ‘. . . work , . . on placenta1 permeability requires to be arranged according to the animal . . . and . . . to the time of gestation’. Grosser’s scheme is discussed in connection with placenta1 evolution, and an intriguing relation between the maternal-fetal ‘distance’ (in terms ofplacental layers) and the morphometric appearance of the transient mesonephros is revealed. As to the nature of the placenta1 barrier it is clearly understood that it must have passive (‘filter’) and more complicated (‘secretory’) functions. The importante of molecular size is recognized, and from the higher concentrations of ‘free amino-acid nitrogen’ in the fetal circulation a ‘regulatory mechanism in the placenta’ is deduced for amino acids which ‘the cells seem to take out of the maternal blood and to “hand on”‘. In the four subsections on ‘Quantitatil-e l_xperiments on . . ,’tables are given that summarize the concentrations of many substances in maternal and fetal blood. It seems somewhat baffling that the quantitative concepts ot permeability (Teorell, 1935) or of clearance are not addressed, even though the significance of the blood streams (including their mutual arrangements) is seen and the necessar)clements were known (Fick, 18.55; Cohnstein and Zuntz, 1884; CE’s tables even give umbilical av-differences for lactate and glucose). Lf71at is the impact of ‘Chemical Embryology’? Firstly, it laid the foundation of a branch ot science, and therefore sustains, to some extent, the activity of al1 ofus who read this journal. It
94
Placenta (1992), Vol. 13
furthermore added momentum to the already rolling bal1 of ‘mechanism’ and thus influenced the course and development of natura1 science generally. Is it worthwhile (for the non-historian) to look into ‘Chemical Embryology’ nowadays (if you can get hold of a copy)? CE certainly is much more than a gigantic old mine that stil1 contains precieus stones. It is rather a guide and map leading through the many aspects of embryology, showing beautiful and surprising outlooks you may never have expected. My favorite trails are the ‘Origin of Chemical Embryology’ which is simply delightful to read, and Section 3, ‘On Increase in Complex@ and Organization’. It provides the framework for many of the sections to come, and it may wel1 be that the reader wil1 find here the roots of his or her own specialty. True, CE also has some flaws. For example, no uniform typography was adopted for the many equations in Section 2 which sometimes leaves the reader helpless and some of the formulae are simply wrong, but this adds a human touch to an otherwise almost super-human mind. This applies also to many spicy and sharp-tongued remarks on the essence of the publications discussed. In summary, you should definitely try ‘Chemical Embryology’. Finally some words on Joseph Needham (Spengler, 1977). Born in 1900 he was educated as a schoolboy at Oundle in ‘practica1 scientific laboratory werk’. He started with biology at Cambridge, but soon moved to biochemistry by joining F. G. Hopkins. In 1924, Caius College elected him as fellow, later the Royal Society also accepted him and his wife Dorothy as fellows. Having started so outstandingly in natura1 sciences he slowly drifted ‘eastward’ focusing his interests more and more on the history of China. His work culminated in the monumental multi-volume ‘Science and Civilisation in China’ (Cambridge, since 1954). To embryology his power of compilation and contemplation was lost. It may help to understand his intellectual capacities if we know (Temple, 1990) that he is fluent in at least eight languages, and that he has a photographic memory allowing him, for example, to proof read his manuscripts ‘in his head’. Joseph Needham is stil1 alive.
REFERENCES Cohnstein, J. & Zuntz, N. (1884) Pjüger? Archir, 34, 173. Fick, A. (1855) Ann. Physik. Chem, 94, 59. Spengler, T. (1977) Wissenschaftlicher Universalismus. Über Bedeuhmg und Besonderheit Wissenschaft. Suhrkamp Verlag, FrankfurtIMain. Temple, R. (1990) Al1 in his head (boek reviews). Yaiature, 348, 59 1. Teorell, T. (1935) Proceedingsof the Socie[yJi>rExperimental BiologyandMedicine, 33, 282. Wells, F. E. (1932) New books and publications. Anatomical Record, 51.
der chinesischen
