About the Book
"1 Jind published lectures insipid. " ALEXANDER VON HUMBOLDT ta LOUIS AGASSIZ, January 15, 1840 Many things speak against the publication of lectures. The effect of the spoken word is very different from that of the written word. Repeated recapitulations, which help the listener under- stand, are unnecessary, and the overtones of speech disappear in print. A lecture, particularly when not meant for beginners and not offered in preparation for a test, permits the privilege of subjective choice, and when published it is rightly open to criticism. So it has not been easy for me to determine to publish these lectures, which I have given in various forms in Gattingen and then again in Tiibingen. In the end, the deciding factors were the urging of my students, the encouragement of colleagues, many of whom I was delighted to see among my listeners, and the wish of my publisher, with whom I have enjoyed a friendly relationship for a long time. The final form of the text is basically a copy, and thus reallectures are the heart of it.
If the lectures had not been taken down repeatedly, this book would not have appeared; 1 could not have undertaken a textbook-sized compilation of this material. With all the changes, the organization, the line of thought, and of ten the composition of the lectures themselves were retained. They may recall to my listeners of old the hours we spent together.
Table of Contents:
Lecture 1. Introduction Fundamental problems and concepts. Developmental physiology of the cell. Basic structure and transformations of the chromosomes; the mitotic cycle, coiling, chromosomal duplication (Figs. 1-10).- Lecture 2. Architecture and chemical composition of the chromosomes. Nucleolar chromosomes, euchromatin, and heterochromatin; role of DNA. Dipteran giant chromosomes; submicroscopic structure of the chromosomes (Figs. 11-33).- Lecture 3. Chromosomal changes in relation to the state of the cell and to the composition of the genome. Meiosis, dependence of its course on internal and external conditions (Figs. 34-46).- Lecture 4. The chromosomal distribution apparatus. Formation and transformation of the spindle; prometaphase and anaphase movements of the chromosomes; aberrant division mechanisms in nature and in experiments (Figs. 47-82).- Lecture 5. Cytoplasmic division; nuclear and cytoplasmic growth (Figs. 83-107).- Lecture 6. Developmental events in unicellular organisms as modification processes. Vegetative and resistant stages, sexual processes; amoebae, Actinophrys, Phytomonads, Foraminiferans, Paramecium (Figs. 108-128).- Lecture 7. Developmental events in acellular open and closed systems. Determination of polarity and organ determination by external and internal conditions; Saprolegnia, Bryopsis, Acetabularia (Figs. 129-148).- Lecture 8. Three morphogenetic principles in the formation of simple multicellular systems; Volvocales, Acrasiales, colonial Chrysomonads (Figs. 149-173).- Lecture 9. Fertilization of the metazoan egg. Sperm entry, union of the pronuclei, activation of development (Figs. 174-185).- Lecture 10. Polarity of the initial cell in the development of multicellular organisms. Bryophyte spores, Pteridophyte spores, Fucus eggs, metazoan eggs (Figs. 186-195).- Lecture 11. Cleavage. Changes in the nucleocytoplasmic ratio; blastula cells in a state of developmental balance; determination of the cleavage pattern; autonomous cyclic cytoplasmic processes; significance of the egg cortex (Figs. 196-205).- Lecture 12. Early development in the echinoids. Normal development; isolation experiments, transplantation experiments, the gradient hypothesis (Figs. 206-229).- Lecture 13. Vegetalization and animalization of echinoid embryos. Biochemical processes, bilaterality, dorsoventrality. Role of the egg cortex (Figs. 230-255).- Lecture 14. Early development in the amphibians. Normal development; structure of the egg, establishment of symmetry, cleavage, morphogenetic movements of gastrulation, movement tendencies of the various blastula regions and their coordination (Figs. 256-276).- Lecture 15. Determination of the pattern of movement tendencies of the various blastula regions, determination of the organization of the blastemas during amphibian gastrulation. The dorsal field, its de novo formation in inversion experiments. Biochemical investigations of the amphibian embryo (Figs. 277-292).- Lecture 16. Earliest differentiation of the germ layers in the amphibians. Fate map of the amphibian blastula. State of determination of presumptive ectoderm, endoderm, and marginal zone material; autonomous differentiation, inductive effects, and reactive competence of the chorda-somite region (Figs. 293-314).- Lecture 17. Morphogenesis of the amphibian nervous system. Normal development. Determination of its organization, region-specific inducers in the chordamesoderm, induction substances, transverse organization of the neural anlage, medio-lateral gradient in the inducer. Self-organization of neural organ fields. Determination of the longitudinal organization of the neural crest by the somites. Secondary inducers. Time course of the determination of competences (Figs. 315-334).- Lecture 18. Self-organization of the chorda-mesodermal field according to a gradient; dependent differentiation of the lateral plates. Development of the eye; field organization of the eye rudiment; determination of lens formation; regulation of dimensions; regeneration during eye development. Developmental activities of the neural crest cells in cartilage in the head and as melanoblasts (Figs. 335-352).- Lecture 19. Interaction of endoderm cells, ectoderm cells, and mesoderm cells in combined explants; model of the formation of hollow endodermal organs. Development of the limbs; role of the mesenchymal blastema and of the ectoderm. Self-organizing fields; inductive fields. Review: conclusions on the causality of normal development (Figs. 353-363).- Lecture 20. Mosaic development in Ascidians. Organ-forming embryonic regions; development of partial embryos without regulation; fusion of embryos; organ-determining substances in the egg cytoplasm (Figs. 364-381).- Lecture 21. Mosaic development in forms with spiral cleavage. Course of cleavage; distribution of cytoplasmic substances. Development of partial embryos, self-differentiation, regulation in the larval stage. Mosaic nature of the egg cytoplasm, larval differentiation without cleavage. Role of the egg cortex; determination of the organization of the Daphnia egg (Figs. 382-398).- Lecture 22. Determination of the body plan in insects. Normal development. Ligation and dissection experiments on embryos; activation center and differentiation center; regulative eggs; stage when the germ band behaves as a self-organizing field; the ectoderm of the germ band as an inductive field. Eggs with early determination; mosaic determination in the cortical cytoplasm of the egg cell. Extent of embryonic determination; imaginal discs; determination of primary germ cells (Figs. 399-429).- Lecture 23. Post-embryonic development in insects. Metamorphosis, three-part hormonal system in Lepidopteran metamorphosis; reactive competence of the epidermis; metamorphosis of implanted integument; repeatability of the steps of metamorphosis; lack of specificity in the metamorphosis hormones (Figs. 430-448).- Lecture 24. Determination of the organ pattern of the adult. Regional determination in the larval epidermis. Regulation in imaginal discs; male genital discs and eye-antenna discs in Drosophila; differential division in the formation of ommatidia (Figs. 449-461).- Lecture 25. Organule pattern in the Lepidopteran wing. Lacunae, tracheae, and nerves. Scale formation. Marginal sense organs. Differential divisions. Field organization of the color patterns (Figs. 462-478).- Lecture 26. Developmental processes in plants. Typical development in a herbaceous plant. Tissue differentiation. Leaf arrangement. Effects of phytohormones on vegetative development (Figs. 479-492).- Lecture 27. Internal and external conditions inducing the flowering phase; temperature and light effects, flowering hormones. Short-day and long-day plants, endogenous rhythms. Morphogenetic substances (Figs. 493-504).- Lecture 28. Differentiation in tissue culture, polarity, testing the effects of phytohormones (Figs. 505-510).- Lecture 29. Pattern differentiation, alternating modifications, differential division, inhibitory fields. Leaf epidermis pattern, relation to the mesophyll (Figs. 511-523).- Lecture 30. Regeneration. Starfish arms. Interstitial cells in hydroids; potential immortality of the individual Hydra. Course of regeneration in Hydra and in Tubularia. Polarity, polar heteromorphosis. Inhibitory substances (Figs. 524-540).- Lecture 31. Regeneration in planarians. Axial gradient. Neoblasts. Epimorphosis and morphallaxis. A mediolateral gradient. Heteromorphoses. Inductive and inhibitory effects (Figs. 541-561).- Lecture 32. Deployment of substances during the processes of differentiation. Morphogenetic phenomena in tissue culture as models of functional design in weight-bearing tissues. Biocrystalline nature of the Echinoderm skeleton; functional structures; nonfunctional correlations (Figs. 562-574).- Lecture 33. The hereditary material as a fundamental condition for morphogenesis. Intracellular and intercellular genetic effects, phenocopies, sensitive periods. Mutation effects in insects, genic effects on the competence of cells, on the organization of fields, and on organ properties (Figs. 575-582).- Lecture 34. Lethal factors as a means of analyzing gene action. Lethal genes in insects. Phase specificity and organ specificity. Pleiotropic pattern of lethal effects. Mutation effects in the vertebrates (Figs. 583-598).- Lecture 35. Developmental physiology and the nature of evolution. Models for the reintegration of organisms after successive mutations. Normal development in Marchantia and its alteration by mutations; parallelism with other genera; a progressive mutation. Xenoplastic transplantation in amphibians. The creative nature of evolution (Figs. 599-610).- Lecture 36. Questions on the role of genes in development. Mutational effects on chemical processes as models. The activation of specific genes. Signs of activity in the chromomeres. Appearance of puffs during metamorphosis; the effect of ecdysone. RNA formation in puffs, protein synthesis in the cytoplasm. Relation to molecular genetics; genetic and developmental primary processes. The problem of determination. Nuclear transplantation. Predetermination, dauermodifications. Hereditary factors in the cytoplasm. Unsolved problems (Figs. 611-620).- References.- Author Index.- Systematic Index.
